usage_options.h

#ifndef OOKII_basic_usage_options_H_
#define OOKII_basic_usage_options_H_
 
#pragma once
 
#include "string_helper.h"
#include "line_wrapping_stream.h"
 
namespace ookii
{
    template<typename CharType, typename Traits = std::char_traits<CharType>, typename Alloc = std::allocator<CharType>>
    class basic_usage_options
    {
    private:
        using line_wrapping_stream_type = basic_line_wrapping_ostream<CharType, Traits>;
 
        std::optional<line_wrapping_stream_type> _owned_output;
        std::optional<line_wrapping_stream_type> _owned_error;
 
    public:
        struct defaults
        {
            static constexpr auto usage_prefix_format = literal_cast<CharType>("Usage: {}");
            static constexpr auto value_description_format = literal_cast<CharType>("<{}>");
            static constexpr auto optional_argument_format = literal_cast<CharType>("[{}]");
            static constexpr auto multi_value_suffix = literal_cast<CharType>("...");
            static constexpr auto argument_description_format = literal_cast<CharType>("    {}{} {}{}\n{}{}\n");
            static constexpr auto default_value_format = literal_cast<CharType>(" Default value: {}.");
            static constexpr auto alias_format = literal_cast<CharType>(" ({})");
            static constexpr auto alias_separator = literal_cast<CharType>(", ");
            
            static constexpr size_t syntax_indent = 3;
            static constexpr size_t argument_description_indent = 8;
        };
 
        using string_type = std::basic_string<CharType, Traits, Alloc>;
        using stream_type = std::basic_ostream<CharType, Traits>;
 
        basic_usage_options()
            : _owned_output{line_wrapping_stream_type::for_cout()},
              _owned_error{line_wrapping_stream_type::for_cerr()},
              output{*_owned_output},
              error{*_owned_error}
        {
 
        }
 
        basic_usage_options(stream_type &output)
            : output{output},
              error{output}
        {
        }
 
        basic_usage_options(stream_type &output, stream_type &error)
            : output{output},
              error{error}
        {
        }
 
        stream_type &output;
 
        stream_type &error;
 
        string_type usage_prefix_format{defaults::usage_prefix_format.data()};
 
        string_type value_description_format{defaults::value_description_format.data()};
 
        string_type optional_argument_format{defaults::optional_argument_format.data()};
 
        string_type multi_value_suffix{defaults::multi_value_suffix.data()};
 
        string_type argument_description_format{defaults::argument_description_format.data()};
 
        string_type default_value_format{defaults::default_value_format.data()};
 
        string_type alias_format{defaults::alias_format.data()};
 
        string_type alias_separator{defaults::alias_separator.data()};
 
        size_t syntax_indent{defaults::syntax_indent};
 
        size_t argument_description_indent{defaults::argument_description_indent};
 
        bool use_white_space_value_separator{true};
 
        bool include_default_value_in_description{true};
 
        bool include_aliases_in_description{true};
    };
 
    using usage_options = basic_usage_options<char>;
    using wusage_options = basic_usage_options<wchar_t>;
}
 
#endif