Cppcheck report - MOAB: src/ProgOptions.cpp

#include <iostream>
#include <sstream>
#include <iomanip>
#include <cstdlib>
#include <list>
#include <limits>
#include <set>
#include <algorithm>

#include <cassert>
#include <cstring>

#include "moab/MOABConfig.h"
#include "moab/ProgOptions.hpp"
#ifdef MOAB_HAVE_MPI
#include "moab_mpi.h"
#endif

enum OptType
{
    FLAG = 0,
    INT,
    REAL,
    STRING,
    INT_VECT
};

template < typename T >
inline static OptType get_opt_type();

template <>
OptType get_opt_type< void >()
{
    return FLAG;
}
template <>
OptType get_opt_type< int >()
{
    return INT;
}
template <>
OptType get_opt_type< double >()
{
    return REAL;
}
template <>
OptType get_opt_type< std::string >()
{
    return STRING;
}
template <>
OptType get_opt_type< std::vector< int > >()
{
    return INT_VECT;
}

class ProgOpt
{

    std::string shortname, longname;
    std::vector< std::string > args;
    OptType type;
    void* storage;
    int flags;
    ProgOpt* cancel_opt;

    const char* get_argstring() const
    {
        switch( type )
        {
            case INT:
                return "int";
            case INT_VECT:
                return "ints";
            case REAL:
                return "val";
            case FLAG:
                return "";
            default:
                return "arg";
        }
    }

  public:
    ProgOpt( const std::string& longname_p, const std::string& shortname_p, int flags_p, OptType t = FLAG )
        : shortname( shortname_p ), longname( longname_p ), type( t ), storage( NULL ), flags( flags_p ),
          cancel_opt( NULL )
    {
    }

    friend class ProgOptions;
};

ProgOptions::ProgOptions( const std::string& helpstring, const std::string& briefhelp )
    : expect_optional_args( false ), optional_args_position( 0 ), max_optional_args( 0 )
{
    brief_help = briefhelp;
<--- Variable 'brief_help' is assigned in constructor body. Consider performing initialization in initialization list. [+]
When an object of a class is created, the constructors of all member variables are called consecutively in the order the variables are declared, even if you don't explicitly write them to the initialization list. You could avoid assigning 'brief_help' a value by passing the value to the constructor in the initialization list.
    if( !helpstring.empty() ) main_help.push_back( helpstring );
    addOpt< void >( "help,h", "Show full help text", help_flag );
}

ProgOptions::~ProgOptions()
{
    for( std::vector< help_line >::iterator i = option_help_strings.begin(); i != option_help_strings.end(); ++i )
    {
        if( ( *i ).first )
        {
            delete( *i ).first;
        }
    }

    for( std::vector< help_line >::iterator i = arg_help_strings.begin(); i != arg_help_strings.end(); ++i )
    {
        delete( *i ).first;
    }
}

void ProgOptions::get_namestrings( const std::string& namestring, std::string* longname, std::string* shortname )
{
    *shortname = "";
    *longname  = namestring;

    size_t idx = namestring.find_first_of( ',' );
    if( idx != namestring.npos )
    {
        *longname  = namestring.substr( 0, idx );
        *shortname = namestring.substr( idx + 1, namestring.npos );
    }
}

void ProgOptions::setVersion( const std::string& version_string, bool addFlag )<--- The function 'setVersion' is never used.
{
    progversion = version_string;
    if( addFlag )
    {
        addOpt< void >( "version", "Print version number and exit", version_flag );
    }
}

template < typename T >
void ProgOptions::addOpt( const std::string& namestring, const std::string& helpstring, T* value, int flags )<--- The function 'addOpt < double >' is never used.<--- The function 'addOpt < int >' is never used.<--- The function 'addOpt < std :: string >' is never used.<--- The function 'addOpt < std :: vector < int > >' is never used.
{

    std::string shortname, longname;
    get_namestrings( namestring, &longname, &shortname );

    if( flags & int_flag )
    {  // short name is implicit for this flag
        if( !shortname.empty() ) error( "Requested short name with int_flag option" );
        if( get_opt_type< T >() != INT ) error( "Requested int_flag for non-integer option" );<--- Condition 'get_opt_type < void >()!=INT' is always true<--- Condition 'get_opt_type < int >()!=INT' is always false<--- Condition 'get_opt_type < double >()!=INT' is always true<--- Condition 'get_opt_type < std :: string >()!=INT' is always true<--- Condition 'get_opt_type < std :: vector < int > >()!=INT' is always true
        if( !number_option_name.empty() ) error( "Requested int_flag for multiple options" );
        number_option_name = longname;
    }

    ProgOpt* opt = new ProgOpt( longname, shortname, flags, get_opt_type< T >() );
    if( value ) opt->storage = value;

    if( longname.length() ) long_names[longname] = opt;
    if( shortname.length() ) short_names[shortname] = opt;

    help_line help = std::make_pair( opt, helpstring );
    option_help_strings.push_back( help );

    if( flags & add_cancel_opt )
    {
        std::string flag    = "no-" + ( longname.length() ? longname : shortname );
        ProgOpt* cancel_opt = new ProgOpt( flag, "", flags ^ ProgOptions::store_false, FLAG );
        if( value ) cancel_opt->storage = value;

        cancel_opt->cancel_opt       = opt;
        long_names[flag]             = cancel_opt;
        std::string clear_helpstring = "Clear previous " + flag.substr( 3, flag.npos ) + " flag";
        help                         = std::make_pair( cancel_opt, clear_helpstring );
        option_help_strings.push_back( help );
    }
}

template < typename T >
void ProgOptions::addRequiredArg( const std::string& helpname, const std::string& helpstring, T* value, int flags )
{

    OptType type = get_opt_type< T >();

    ProgOpt* opt = new ProgOpt( helpname, "", flags, type );
    if( value ) opt->storage = value;
    help_line help = std::make_pair( opt, helpstring );
    arg_help_strings.push_back( help );
    required_args[helpname] = opt;
}

template < typename T >
void ProgOptions::addOptionalArgs( unsigned max_count,<--- The function 'addOptionalArgs < double >' is never used.<--- The function 'addOptionalArgs < int >' is never used.<--- The function 'addOptionalArgs < std :: string >' is never used.<--- The function 'addOptionalArgs < std :: vector < int > >' is never used.
                                   const std::string& helpname,
                                   const std::string& helpstring,
                                   int flags )
{
    // If there was a previous one, we need to remove it
    // because there can be only one.  If we didn't remove
    // the old one then it would be treated as a required arg.
    if( expect_optional_args )
    {
        std::map< std::string, ProgOpt* >::iterator iter;
        iter = required_args.find( arg_help_strings[optional_args_position].second );
        assert( iter != required_args.end() );
        delete iter->second;
        required_args.erase( iter );
        arg_help_strings.erase( arg_help_strings.begin() + optional_args_position );
    }

    expect_optional_args   = true;
    optional_args_position = arg_help_strings.size();
    max_optional_args      = max_count;
    addRequiredArg< T >( helpname, helpstring, 0, flags );
}

void ProgOptions::addOptionHelpHeading( const std::string& s )
{
    option_help_strings.push_back( std::make_pair( (ProgOpt*)NULL, s ) );
}

void ProgOptions::printVersion( std::ostream& out )
{
    out << progversion << std::endl;
}

void ProgOptions::printHelp( std::ostream& out )
{

    /* Print introductory help text */
    if( !brief_help.empty() ) out << brief_help << std::endl;
    for( std::vector< std::string >::iterator i = main_help.begin(); i != main_help.end(); ++i )
    {
        if( ( *i ).length() )
        {
            out << std::endl << *i << std::endl;
        }
    }

    printUsage( out );

    // max number of characters to pad argument/option names with
    // options with long names may exceed this, but will appear out of alignment in help text
    const int max_padding = 20;

    /* List required arguments, with help text */
    if( arg_help_strings.size() > 0 )
    {

        int max_arg_namelen = 0;

        for( std::vector< help_line >::iterator i = arg_help_strings.begin(); i != arg_help_strings.end(); ++i )
        {
            max_arg_namelen = std::max( max_arg_namelen, (int)( ( *i ).first->longname.length() ) );
        }

        max_arg_namelen = std::min( max_arg_namelen + 3, max_padding );

        out << "Arguments: " << std::endl;

        for( std::vector< help_line >::iterator i = arg_help_strings.begin(); i != arg_help_strings.end(); ++i )
        {
            ProgOpt* option   = ( *i ).first;
            std::string& info = ( *i ).second;

            std::stringstream s;
            s << "  " << option->longname;
            out << std::setw( max_arg_namelen ) << std::left << s.str();
            out << ": " << info << std::endl;
        }
    }

    /* List options, with help text */
    out << "Options: " << std::endl;
    int max_option_prefix_len = 0;

    for( std::vector< help_line >::iterator i = option_help_strings.begin(); i != option_help_strings.end(); ++i )
    {
        ProgOpt* option   = ( *i ).first;
        std::string& info = ( *i ).second;

        if( option )
        {

            if( max_option_prefix_len == 0 )
            {
                // iterate ahead in the option list to determine whitespace padding
                // stop if (*j).first is NULL, which indicates a help header message
                for( std::vector< help_line >::iterator j = i; j != option_help_strings.end() && ( *j ).first; ++j )
                {
                    int len               = get_option_usage_prefix( *( ( *j ).first ) ).length();
                    max_option_prefix_len = std::max( max_option_prefix_len, len );
                }
            }
            max_option_prefix_len     = std::min( max_option_prefix_len, max_padding );
            std::string option_prefix = get_option_usage_prefix( *option );

            out << std::setw( max_option_prefix_len ) << std::left << option_prefix;
            out << ": ";
        }
        else
        {
            // no option: this is a help header.  Reset max name length.
            max_option_prefix_len = 0;
        }
        out << info << std::endl;
    }
}

std::string ProgOptions::get_option_usage_prefix( const ProgOpt& option )
{
    bool has_shortname = option.shortname.length() > 0;
    bool has_longname  = option.longname.length() > 0;
    std::string argstr = option.get_argstring();

    std::stringstream s;
    s << "  ";
    if( has_shortname )
    {

        s << "-" << option.shortname;
        if( has_longname )
        {
            s << " ";
        }
    }
    else if( option.flags & int_flag )
    {

        s << "-<n>";
        if( has_longname )
        {
            s << " ";
        }
    }
    if( has_longname )
    {

        if( has_shortname ) s << "[";
        s << "--" << option.longname;
        if( has_shortname ) s << "]";
    }

    if( argstr.length() ) s << " <" << argstr << ">";
    return s.str();
}

void ProgOptions::printUsage( std::ostream& out )
{

    out << "Usage: " << progname << " --help | [options] ";

    for( size_t i = 0; i < arg_help_strings.size(); ++i )
    {
        if( !expect_optional_args || i != optional_args_position )
            out << '<' << arg_help_strings[i].first->longname << "> ";
        else if( 0 == max_optional_args || max_optional_args > 3 )
            out << "[<" << arg_help_strings[i].first->longname << "> ...] ";
        else if( 1 == max_optional_args )
            out << "[" << arg_help_strings[i].first->longname << "] ";
        else
            for( unsigned j = 0; j < max_optional_args; ++j )
                out << "[" << arg_help_strings[i].first->longname << ( j + 1 ) << "] ";
    }

    out << std::endl;
}

ProgOpt* ProgOptions::lookup( const std::map< std::string, ProgOpt* >& table, const std::string& arg )
{
    std::map< std::string, ProgOpt* >::const_iterator it = table.find( arg );
    if( it != table.end() )
        return it->second;
    else if( &table == &short_names && arg.size() == 1 && isdigit( arg[0] ) && !number_option_name.empty() &&
             ( it = long_names.find( number_option_name ) ) != long_names.end() )
        return it->second;
    else
        return 0;
}

ProgOpt* ProgOptions::lookup_option( const std::string& namestring )
{
    std::string longname, shortname;
    get_namestrings( namestring, &longname, &shortname );

    ProgOpt* opt = lookup( long_names, longname );
    if( !opt ) opt = lookup( short_names, shortname );

    if( !opt )
    {
        error( "Invalid option: " + namestring );
    }

    return opt;
}

void ProgOptions::error( const std::string& err )
{
    std::cerr << "Error: " << err << "\n" << std::endl;
    ;
    printUsage( std::cerr );
    std::cerr << std::endl;
    if( getenv( "MOAB_PROG_OPT_ABORT" ) ) abort();
    std::exit( EXIT_FAILURE );
}

// Copied from convert.cpp
// Parse list of integer ranges
// e.g. 1,2,5-10,12
static bool parse_int_list( const char* string, std::vector< int >& results )
{
    bool okay   = true;
    char* mystr = strdup( string );
    for( const char* ptr = strtok( mystr, ", \t" ); ptr; ptr = strtok( 0, ", \t" ) )
    {
        char* endptr;
        long val = strtol( ptr, &endptr, 0 );
        if( endptr == ptr )
        {
            std::cerr << "Not an integer: \"" << ptr << '"' << std::endl;
            okay = false;
            break;
        }

        long val2 = val;
        if( *endptr == '-' )
        {
            const char* sptr = endptr + 1;
            val2             = strtol( sptr, &endptr, 0 );
            if( endptr == sptr )
            {
                std::cerr << "Not an integer: \"" << sptr << '"' << std::endl;
                okay = false;
                break;
            }
            if( val2 < val )
            {
                std::cerr << "Invalid id range: \"" << ptr << '"' << std::endl;
                okay = false;
                break;
            }
        }

        if( *endptr )
        {
            okay = false;
            break;
        }

        for( ; val <= val2; ++val )
            results.push_back( (int)val );
    }

    free( mystr );
    return okay;
}

// Copied from convert.cpp
// Replace '%' with MPI rank iff compiled with MPI
static std::string do_rank_subst( const std::string& s )
{
#ifndef MOAB_HAVE_MPI
    return s;
#else
    int rank, size;
    if( MPI_SUCCESS != MPI_Comm_rank( MPI_COMM_WORLD, &rank ) || MPI_SUCCESS != MPI_Comm_size( MPI_COMM_WORLD, &size ) )
        return s;
    int width = 1;
    while( size > 10 )
    {
        size /= 10;
        width++;
    }

    size_t j = s.find( '%' );
    if( j == std::string::npos ) return s;

    std::ostringstream st;
    st << std::setfill( '0' );
    st << s.substr( 0, j );
    st << rank;

    size_t i;
    while( ( i = s.find( '%', j + 1 ) ) != std::string::npos )
    {
        st << s.substr( j, i - j );
        st << std::setw( width ) << rank;
        j = i;
    }
    st << s.substr( j + 1 );
    return st.str();
#endif
}

/**
 * Check the input to a given option for correctness, converting it to its expected type (e.g. int)
 * and storing the result to target, if target is non-NULL.
 * @param option Used only in error messages to state which option could not be successfully
 * converted
 * @param arg_idx If non-NULL, evaluate the (*arg_idx)'th item in opt's args list
 */
bool ProgOptions::evaluate( const ProgOpt& opt, void* target, const std::string& option, unsigned* arg_idx )
{

    unsigned idx = arg_idx ? *arg_idx : opt.args.size() - 1;

    switch( opt.type )
    {
        case FLAG:
            error( "Cannot evaluate a flag" );
            break;
        case INT: {
            int temp;
            int* i = target ? reinterpret_cast< int* >( target ) : &temp;
            if( opt.args.size() < 1 )
            {
                error( "Missing argument to " + option + " option" );
            }
            const char* arg = opt.args.at( idx ).c_str();
            char* p;
            *i = std::strtol( arg, &p, 0 );
            if( *p != '\0' )
            {
                error( "Bad integer argument '" + opt.args.at( idx ) + "' to " + option + " option." );
            }
            return true;
        }
        case REAL: {
            double temp;
            double* i = target ? reinterpret_cast< double* >( target ) : &temp;
            if( opt.args.size() < 1 )
            {
                error( "Missing argument to " + option + " option" );
            }
            const char* arg = opt.args.at( idx ).c_str();
            char* p;
            *i = std::strtod( arg, &p );
            if( *p != '\0' )
            {
                error( "Bad real argument '" + opt.args.at( idx ) + "' to " + option + " option." );
            }
            return true;
        }

        case STRING: {
            std::string temp;
            std::string* i = target ? reinterpret_cast< std::string* >( target ) : &temp;
            if( opt.args.size() < 1 )
            {
                error( "Missing argument to " + option + " option" );
            }
            if( opt.flags & rank_subst )
                *i = do_rank_subst( opt.args.at( idx ) );
            else
                *i = opt.args.at( idx );
            return true;
        }

        case INT_VECT: {
            std::vector< int > temp;
            std::vector< int >* i = target ? reinterpret_cast< std::vector< int >* >( target ) : &temp;
            if( !parse_int_list( opt.args.at( idx ).c_str(), *i ) )
                error( "Bad integer list '" + opt.args.at( idx ) + "' to " + option + " option." );
            return true;
        }
    }

    return false;
}

template < typename T >
bool ProgOptions::getOpt( const std::string& namestring, T* t )<--- The function 'getOpt < double >' is never used.<--- The function 'getOpt < int >' is never used.<--- The function 'getOpt < std :: string >' is never used.<--- The function 'getOpt < std :: vector < int > >' is never used.<--- The function 'getOpt < void >' is never used.
{

    ProgOpt* opt = lookup_option( namestring );

    if( get_opt_type< T >() != opt->type )
    {
        error( "Option '" + namestring + "' looked up with incompatible type" );
    }

    // This call to evaluate is inefficient, because opt was already evaluated when it was parsed.
    if( opt->args.size() )
    {
        if( t ) evaluate( *opt, t, "" );
        return true;
    }
    else
        return false;
}

template < typename T >
void ProgOptions::getOptAllArgs( const std::string& namestring, std::vector< T >& values )<--- The function 'getOptAllArgs < double >' is never used.<--- The function 'getOptAllArgs < int >' is never used.<--- The function 'getOptAllArgs < std :: string >' is never used.<--- The function 'getOptAllArgs < std :: vector < int > >' is never used.
{
    ProgOpt* opt = lookup_option( namestring );

    // special case: if user asks for list of int, but argument
    // was INT_VECT, concatenate all lists
    if( get_opt_type< T >() == INT && opt->type == INT_VECT )<--- Condition 'get_opt_type < int >()==INT' is always true<--- Condition 'get_opt_type < double >()==INT' is always false<--- Condition 'get_opt_type < std :: string >()==INT' is always false<--- Condition 'get_opt_type < std :: vector < int > >()==INT' is always false
    {
        for( unsigned i = 0; i < opt->args.size(); ++i )
            evaluate( *opt, &values, "", &i );
        return;
    }

    if( get_opt_type< T >() != opt->type )
    {
        error( "Option '" + namestring + "' looked up with incompatible type" );
    }

    values.resize( opt->args.size() );

    // These calls to evaluate are inefficient, because the arguments were evaluated when they were
    // parsed
    for( unsigned i = 0; i < opt->args.size(); ++i )
    {
        evaluate( *opt, &( values[i] ), "", &i );
    }
}

int ProgOptions::numOptSet( const std::string& namestring )
{
    std::string longname, shortname;
    get_namestrings( namestring, &longname, &shortname );

    ProgOpt* opt = lookup( long_names, longname );
    if( !opt ) opt = lookup( short_names, shortname );

    if( !opt )
    {
        error( "Could not look up option: " + namestring );
    }

    return opt->args.size();
}

template < typename T >
T ProgOptions::getReqArg( const std::string& namestring )<--- The function 'getReqArg < double >' is never used.<--- The function 'getReqArg < int >' is never used.<--- The function 'getReqArg < std :: string >' is never used.<--- The function 'getReqArg < std :: vector < int > >' is never used.
{

    ProgOpt* opt = lookup( required_args, namestring );

    if( !opt )
    {
        error( "Could not look up required arg: " + namestring );
    }

    // if parseProgramOptions succeeded, we can assume each required arg has a value,
    // so calling evaluate is valid
    T value;
    evaluate( *opt, &value, "" );
    return value;
}

template < typename T >
void ProgOptions::getArgs( const std::string& namestring, std::vector< T >& values )<--- The function 'getArgs < double >' is never used.<--- The function 'getArgs < int >' is never used.<--- The function 'getArgs < std :: string >' is never used.<--- The function 'getArgs < std :: vector < int > >' is never used.
{
    ProgOpt* opt = lookup( required_args, namestring );

    if( !opt )
    {
        error( "Could not look up required arg: " + namestring );
    }

    if( get_opt_type< T >() != opt->type )
    {
        error( "Option '" + namestring + "' looked up with incompatible type" );
    }

    values.resize( opt->args.size() );

    // These calls to evaluate are inefficient, because the arguments were evaluated when they were
    // parsed
    for( unsigned i = 0; i < opt->args.size(); ++i )
    {
        evaluate( *opt, &( values[i] ), "", &i );
    }
}

// Process parsed option.
// Returns true if value is still expected
// Should never return true if optional value is passed
// \param arg Used for error messages only
bool ProgOptions::process_option( ProgOpt* opt, std::string arg, const char* value )
<--- Function parameter 'arg' should be passed by const reference. [+]
Parameter 'arg' is passed by value. It could be passed as a const reference which is usually faster and recommended in C++.
{
    if( !opt )
    {
        if( arg == "--manpage" )
        {
            write_man_page( std::cout );
            exit( 0 );
        }

        error( "Unknown option: " + arg );
    }

    if( opt->flags & help_flag )
    {
        printHelp( std::cout );
        exit( EXIT_SUCCESS );
    }

    if( opt->flags & version_flag )
    {
        printVersion( std::cout );
        exit( EXIT_SUCCESS );
    }

    if( opt->type != FLAG )
    {
        if( !value ) return true;

        opt->args.push_back( value );
        evaluate( *opt, opt->storage, arg );
    }
    else
    {
        if( value )
        {
            error( "Unexpected value for flag: " + arg );
        }

        // do flag operations
        if( opt->cancel_opt )
        {
            opt->cancel_opt->args.clear();
        }
        if( opt->storage )
        {
            *static_cast< bool* >( opt->storage ) = ( opt->flags & store_false ) ? false : true;
        }
        opt->args.push_back( "" );
    }

    return false;
}

void ProgOptions::parseCommandLine( int argc, char* argv[] )
{
    const char* name = strrchr( argv[0], '/' );
    if( name )
        this->progname = ++name;
    else
        this->progname = argv[0];

    std::vector< const char* > args;
    std::list< ProgOpt* > expected_vals;
    bool no_more_flags = false;

    // Loop over all command line arguments
    for( int i = 1; i < argc; ++i )
    {
        std::string arg( argv[i] );
        if( arg.empty() ) continue;

        if( !expected_vals.empty() )
        {
            ProgOpt* opt = expected_vals.front();
            expected_vals.pop_front();
            assert( opt->type != FLAG );
            opt->args.push_back( arg );
            evaluate( *opt, opt->storage, arg );
        }
        else if( !no_more_flags && arg[0] == '-' )
        {
            if( arg.length() > 2 && arg[1] == '-' )
            {  // long opt
                size_t eq = arg.find_first_of( '=' );
                if( eq != std::string::npos )
                {
                    ProgOpt* opt = lookup( long_names, arg.substr( 2, eq - 2 ) );
                    process_option( opt, arg, arg.substr( eq + 1 ).c_str() );
                }
                else
                {
                    ProgOpt* opt = lookup( long_names, arg.substr( 2 ) );
                    if( process_option( opt, arg ) ) expected_vals.push_back( opt );
                }
            }
            else if( arg == "--" )
            {  // --
                no_more_flags = true;
            }
            else
                for( size_t f = 1; f < arg.length(); ++f )
                {  // for each short opt
                    ProgOpt* opt = lookup( short_names, std::string( 1, arg[f] ) );
                    if( opt && ( opt->flags & int_flag ) )
                    {
                        const char val[] = { arg[f], 0 };
                        process_option( opt, std::string( 1, arg[f] ), val );
                    }
                    else if( process_option( opt, std::string( 1, arg[f] ) ) )
                        expected_vals.push_back( opt );
                }
        }
        else
        {
            /* arguments */
            args.push_back( argv[i] );
        }
    } /* End loop over inputs */

    // Print error if any missing values
    if( !expected_vals.empty() )
    {
        error( "Missing value for option: -" + expected_vals.front()->shortname + ",--" +
               expected_vals.front()->longname );
    }

    // Process non-option arguments
    std::vector< help_line >::iterator arg_help_pos  = arg_help_strings.begin();
    std::vector< const char* >::iterator arg_val_pos = args.begin();
    std::vector< help_line >::iterator opt_args_pos  = arg_help_strings.end();
    size_t min_required_args                         = required_args.size();
<--- Same expression used in consecutive assignments of 'min_required_args' and 'max_required_args'. [+]
Finding variables 'min_required_args' and 'max_required_args' that are assigned the same expression is suspicious and might indicate a cut and paste or logic error. Please examine this code carefully to determine if it is correct.
    size_t max_required_args                         = required_args.size();
<--- Same expression used in consecutive assignments of 'min_required_args' and 'max_required_args'. [+]
Finding variables 'min_required_args' and 'max_required_args' that are assigned the same expression is suspicious and might indicate a cut and paste or logic error. Please examine this code carefully to determine if it is correct.
    if( expect_optional_args )
    {
        min_required_args--;
        if( max_optional_args )
            max_required_args += max_optional_args;
        else
            max_required_args = std::numeric_limits< int >::max();
        opt_args_pos = arg_help_pos + optional_args_position;
    }
    // check valid number of non-flag arguments
    if( args.size() < min_required_args )
    {
        size_t missing_pos = args.size();
        if( expect_optional_args && missing_pos >= optional_args_position ) ++missing_pos;

        const std::string& missed_arg = arg_help_strings[missing_pos].first->longname;
        error( "Did not find required positional argument: " + missed_arg );
    }
    else if( args.size() > max_required_args )
    {
        error( "Unexpected argument: " + std::string( args[max_required_args] ) );
    }

    // proccess arguments up to the first optional argument
    // (or all arguments if no optional args)
    while( arg_help_pos != opt_args_pos )
    {
        ProgOpt* opt = arg_help_pos->first;
        ++arg_help_pos;
        opt->args.push_back( *arg_val_pos );
        evaluate( *opt, opt->storage, *arg_val_pos );
        ++arg_val_pos;
    }
    // process any optional args
    if( arg_help_pos != arg_help_strings.end() )
    {
        assert( arg_help_pos == opt_args_pos );
        size_t num_opt_args = args.size() + 1 - required_args.size();
        ProgOpt* opt        = arg_help_pos->first;
        ++arg_help_pos;
        while( num_opt_args-- )
        {
            opt->args.push_back( *arg_val_pos );
            evaluate( *opt, opt->storage, *arg_val_pos );
            ++arg_val_pos;
        }
    }
    // process any remaining args
    while( arg_help_pos != arg_help_strings.end() )
    {
        assert( arg_val_pos != args.end() );
        ProgOpt* opt = arg_help_pos->first;
        ++arg_help_pos;
        opt->args.push_back( *arg_val_pos );
        evaluate( *opt, opt->storage, *arg_val_pos );
        ++arg_val_pos;
    }
    assert( arg_val_pos == args.end() );
}

void ProgOptions::write_man_page( std::ostream& s )
{
    // a leading '.' is a control character.  strip it if present.
    std::string lprogname;
    if( progname.empty() || progname[0] != '.' )
        lprogname = progname;
    else
    {
        lprogname = progname.substr( 1 );
    }

    // Manpage controls:
    // .TH title
    // .SH section
    // .SS subsection
    // .P  paragraph
    // .HP hanging paragraph
    // .B  bold
    // .I  italic
    // .B  bold
    // .I  italic
    // .RS begin indent
    // .RE end indent
    // .RB alternating roman and blold
    // .BR alternating bold and roman

    std::vector< help_line >::iterator it;
    std::set< ProgOpt* > skip_list;

    // start man page
    s << std::endl << ".TH " << lprogname << " 1" << std::endl;

    // write NAME section
    s << std::endl << ".SH NAME" << std::endl << ".P " << std::endl << lprogname << " \\- ";
    if( brief_help.empty() && !main_help.empty() )
        s << main_help.front();
    else
        s << brief_help;
    s << std::endl << std::endl;

    // write SYNOPSIS section
    s << std::endl << ".SH SYNOPSIS" << std::endl << ".HP" << std::endl << ".B \"" << lprogname << '"' << std::endl;
    for( it = option_help_strings.begin(); it != option_help_strings.end(); ++it )
    {
        if( !it->first || skip_list.find( it->first ) != skip_list.end() || it->first->longname == "help" ) continue;

        if( it->first->type == FLAG )
        {
            char c = '[';
            s << ".RB";
            if( !it->first->shortname.empty() )
            {
                s << ' ' << c << " \"-" << it->first->shortname << '"';
                c = '|';
            }
            if( !it->first->longname.empty() )
            {
                s << ' ' << c << " \"--" << it->first->longname << '"';
            }
            if( it->first->cancel_opt )
            {
                skip_list.insert( it->first->cancel_opt );
                if( !it->first->cancel_opt->shortname.empty() )
                    s << " | \"-" << it->first->cancel_opt->shortname << '"';
                if( !it->first->cancel_opt->longname.empty() ) s << " | \"--" << it->first->cancel_opt->longname << '"';
            }
            s << " ]" << std::endl;
        }
        else if( it->first->flags & int_flag )
        {
            s << ".RB [ - <n>| \"--" << it->first->longname << "\" \"=" << it->first->get_argstring() << "]\""
              << std::endl;
        }
        else
        {
            s << ".RB [ ";
            if( !it->first->shortname.empty() )
                s << "\"-" << it->first->shortname << "\" \"\\ " << it->first->get_argstring();
            if( !it->first->shortname.empty() && !it->first->longname.empty() ) s << "|\" ";
            if( !it->first->longname.empty() )
                s << "\"--" << it->first->longname << "\" \"=" << it->first->get_argstring();
            s << "]\"" << std::endl;
        }
    }
    for( it = arg_help_strings.begin(); it != arg_help_strings.end(); ++it )
    {
        if( !it->first ) continue;

        if( !expect_optional_args || (unsigned)( it - arg_help_strings.begin() ) != optional_args_position )
            s << it->first->longname << ' ';
        else if( 1 == max_optional_args )
            s << '[' << it->first->longname << "] ";
        else
            s << '[' << it->first->longname << " ...] ";
    }
    s << std::endl;
    s << ".HP" << std::endl << ".B \"" << lprogname << " -h|--help\"" << std::endl;

    // write DESCRIPTION section
    s << std::endl << ".SH DESCRIPTION" << std::endl;
    if( main_help.empty() ) s << brief_help << std::endl;
    for( size_t i = 0; i < main_help.size(); ++i )
    {
        const std::string::size_type n = main_help[i].size();
        std::string::size_type j       = 0, k;
        s << std::endl << ".P" << std::endl;
        while( j != n )
        {
            if( main_help[i][j] == '\n' )
            {
                s << std::endl << ".P" << std::endl;
                ++j;
                continue;
            }
            k = main_help[i].find( "\n", j );
            if( k == std::string::npos ) k = n;
            if( main_help[i][j] == '.' ) s << '\\';
            s << main_help[i].substr( j, k - j );
            j = k;
        }
    }

    // write OPTIONS section
    s << std::endl << ".SH OPTIONS" << std::endl;
    for( it = arg_help_strings.begin(); it != arg_help_strings.end(); ++it )
    {
        if( it->first )
            s << ".IP \"" << it->first->longname << '"' << std::endl << it->second << std::endl;
        else
            s << ".SS " << it->first->longname << std::endl;
    }
    for( it = option_help_strings.begin(); it != option_help_strings.end(); ++it )
    {
        if( !it->first )
        {
            s << ".SS " << it->second << std::endl;
            continue;
        }

        s << ".IP \"";
        if( it->first->longname.empty() )
            s << "-" << it->first->shortname;
        else if( it->first->shortname.empty() )
            s << "--" << it->first->longname;
        else
            s << "-" << it->first->shortname << ", --" << it->first->longname;
        s << '"' << std::endl << it->second << std::endl;
    }
    s << std::endl;
}

/* Ensure g++ instantiates the template types we expect to use */

#define DECLARE_OPTION_TYPE( T )                                                               \
    template void ProgOptions::addOpt< T >( const std::string&, const std::string&, T*, int ); \
    template bool ProgOptions::getOpt< T >( const std::string&, T* );

#define DECLARE_VALUED_OPTION_TYPE( T )                                                                       \
    DECLARE_OPTION_TYPE( T )                                                                                  \
    template void ProgOptions::getOptAllArgs< T >( const std::string&, std::vector< T >& );                   \
    template void ProgOptions::addRequiredArg< T >( const std::string&, const std::string&, T*, int );        \
    template void ProgOptions::addOptionalArgs< T >( unsigned, const std::string&, const std::string&, int ); \
    template T ProgOptions::getReqArg< T >( const std::string& );                                             \
    template void ProgOptions::getArgs< T >( const std::string&, std::vector< T >& );

DECLARE_OPTION_TYPE( void )
DECLARE_VALUED_OPTION_TYPE( int )
DECLARE_VALUED_OPTION_TYPE( double )
DECLARE_VALUED_OPTION_TYPE( std::string )
DECLARE_VALUED_OPTION_TYPE( std::vector< int > )