fmtlib_printf.h

#pragma once
// Formatting library for C++ - legacy printf implementation
//
// Copyright (c) 2012 - 2016, Victor Zverovich
// All rights reserved.
//
// For the license information refer to fmtlib_format.h.

#ifndef CATA_SRC_FMTLIB_PRINTF_H
#define CATA_SRC_FMTLIB_PRINTF_H

#include <algorithm>  // std::max
#include <limits>     // std::numeric_limits

#include "fmtlib_ostream.h"

FMT_BEGIN_NAMESPACE
namespace detail
{

// Checks if a value fits in int - used to avoid warnings about comparing
// signed and unsigned integers.
template <bool IsSigned> struct int_checker {
    template <typename T> static bool fits_in_int( T value ) {
        unsigned max = max_value<int>();
        return value <= max;
    }
    static bool fits_in_int( bool ) {
        return true;
    }
};

template <> struct int_checker<true> {
    template <typename T> static bool fits_in_int( T value ) {
        return value >= ( std::numeric_limits<int>::min )() &&
               value <= max_value<int>();
    }
    static bool fits_in_int( int ) {
        return true;
    }
};

class printf_precision_handler
{
    public:
        template <typename T, FMT_ENABLE_IF( std::is_integral<T>::value )>
        int operator()( T value ) {
            if( !int_checker<std::numeric_limits<T>::is_signed>::fits_in_int( value ) ) {
                FMT_THROW( format_error( "number is too big" ) );
            }
            return ( std::max )( static_cast<int>( value ), 0 );
        }

        template < typename T, FMT_ENABLE_IF( !std::is_integral<T>::value ) >
        int operator()( T ) {
            FMT_THROW( format_error( "precision is not integer" ) );
            return 0;
        }
};

// An argument visitor that returns true iff arg is a zero integer.
class is_zero_int
{
    public:
        template <typename T, FMT_ENABLE_IF( std::is_integral<T>::value )>
        bool operator()( T value ) {
            return value == 0;
        }

        template < typename T, FMT_ENABLE_IF( !std::is_integral<T>::value ) >
        bool operator()( T ) {
            return false;
        }
};

template <typename T> struct make_unsigned_or_bool : std::make_unsigned<T> {};

template <> struct make_unsigned_or_bool<bool> {
    using type = bool;
};

template <typename T, typename Context> class arg_converter
{
    private:
        using char_type = typename Context::char_type;

        basic_format_arg<Context> &arg_;
        char_type type_;

    public:
        arg_converter( basic_format_arg<Context> &arg, char_type type )
            : arg_( arg ), type_( type ) {}

        void operator()( bool value ) {
            if( type_ != 's' ) {
                operator()<bool>( value );
            }
        }

        template <typename U, FMT_ENABLE_IF( std::is_integral<U>::value )>
        void operator()( U value ) {
            bool is_signed = type_ == 'd' || type_ == 'i';
            using target_type = conditional_t<std::is_same<T, void>::value, U, T>;
            if( const_check( sizeof( target_type ) <= sizeof( int ) ) ) {
                // Extra casts are used to silence warnings.
                if( is_signed ) {
                    arg_ = detail::make_arg<Context>(
                               static_cast<int>( static_cast<target_type>( value ) ) );
                } else {
                    using unsigned_type = typename make_unsigned_or_bool<target_type>::type;
                    arg_ = detail::make_arg<Context>(
                               static_cast<unsigned>( static_cast<unsigned_type>( value ) ) );
                }
            } else {
                if( is_signed ) {
                    // glibc's printf doesn't sign extend arguments of smaller types:
                    //   std::printf("%lld", -42);  // prints "4294967254"
                    // but we don't have to do the same because it's a UB.
                    arg_ = detail::make_arg<Context>( static_cast<long long>( value ) );
                } else {
                    arg_ = detail::make_arg<Context>(
                               static_cast<typename make_unsigned_or_bool<U>::type>( value ) );
                }
            }
        }

        template < typename U, FMT_ENABLE_IF( !std::is_integral<U>::value ) >
        void operator()( U ) {} // No conversion needed for non-integral types.
};

// Converts an integer argument to T for printf, if T is an integral type.
// If T is void, the argument is converted to corresponding signed or unsigned
// type depending on the type specifier: 'd' and 'i' - signed, other -
// unsigned).
template <typename T, typename Context, typename Char>
void convert_arg( basic_format_arg<Context> &arg, Char type )
{
    visit_format_arg( arg_converter<T, Context>( arg, type ), arg );
}

// Converts an integer argument to char for printf.
template <typename Context> class char_converter
{
    private:
        basic_format_arg<Context> &arg_;

    public:
        explicit char_converter( basic_format_arg<Context> &arg ) : arg_( arg ) {}

        template <typename T, FMT_ENABLE_IF( std::is_integral<T>::value )>
        void operator()( T value ) {
            arg_ = detail::make_arg<Context>(
                       static_cast<typename Context::char_type>( value ) );
        }

        template < typename T, FMT_ENABLE_IF( !std::is_integral<T>::value ) >
        void operator()( T ) {} // No conversion needed for non-integral types.
};

// An argument visitor that return a pointer to a C string if argument is a
// string or null otherwise.
template <typename Char> struct get_cstring {
    template <typename T> const Char *operator()( T ) {
        return nullptr;
    }
    const Char *operator()( const Char *s ) {
        return s;
    }
};

// Checks if an argument is a valid printf width specifier and sets
// left alignment if it is negative.
template <typename Char> class printf_width_handler
{
    private:
        using format_specs = basic_format_specs<Char>;

        format_specs &specs_;

    public:
        explicit printf_width_handler( format_specs &specs ) : specs_( specs ) {}

        template <typename T, FMT_ENABLE_IF( std::is_integral<T>::value )>
        unsigned operator()( T value ) {
            auto width = static_cast<uint32_or_64_or_128_t<T>>( value );
            if( detail::is_negative( value ) ) {
                specs_.align = align::left;
                width = 0 - width;
            }
            unsigned int_max = max_value<int>();
            if( width > int_max ) {
                FMT_THROW( format_error( "number is too big" ) );
            }
            return static_cast<unsigned>( width );
        }

        template < typename T, FMT_ENABLE_IF( !std::is_integral<T>::value ) >
        unsigned operator()( T ) {
            FMT_THROW( format_error( "width is not integer" ) );
            return 0;
        }
};

template <typename Char, typename Context>
void vprintf( buffer<Char> &buf, basic_string_view<Char> format,
              basic_format_args<Context> args )
{
    Context( buffer_appender<Char>( buf ), format, args ).format();
}
}  // namespace detail

// For printing into memory_buffer.
template <typename Char, typename Context>
FMT_DEPRECATED void printf( detail::buffer<Char> &buf,
                            basic_string_view<Char> format,
                            basic_format_args<Context> args )
{
    return detail::vprintf( buf, format, args );
}
using detail::vprintf;

template <typename Char>
class basic_printf_parse_context : public basic_format_parse_context<Char>
{
        using basic_format_parse_context<Char>::basic_format_parse_context;
};
template <typename OutputIt, typename Char> class basic_printf_context;

/**
  \rst
  The ``printf`` argument formatter.
  \endrst
 */
template <typename OutputIt, typename Char>
class printf_arg_formatter : public detail::arg_formatter_base<OutputIt, Char>
{
    public:
        using iterator = OutputIt;

    private:
        using char_type = Char;
        using base = detail::arg_formatter_base<OutputIt, Char>;
        using context_type = basic_printf_context<OutputIt, Char>;

        context_type &context_;

        void write_null_pointer( char ) {
            this->specs()->type = 0;
            this->write( "(nil)" );
        }

        void write_null_pointer( wchar_t ) {
            this->specs()->type = 0;
            this->write( L"(nil)" );
        }

    public:
        using format_specs = typename base::format_specs;

        /**
          \rst
          Constructs an argument formatter object.
          *buffer* is a reference to the output buffer and *specs* contains format
          specifier information for standard argument types.
          \endrst
         */
        printf_arg_formatter( iterator iter, format_specs &specs, context_type &ctx )
            : base( iter, &specs, detail::locale_ref() ), context_( ctx ) {}

        template <typename T, FMT_ENABLE_IF( fmt::detail::is_integral<T>::value )>
        iterator operator()( T value ) {
            // MSVC2013 fails to compile separate overloads for bool and char_type so
            // use std::is_same instead.
            if( std::is_same<T, bool>::value ) {
                format_specs &fmt_specs = *this->specs();
                if( fmt_specs.type != 's' ) {
                    return base::operator()( value ? 1 : 0 );
                }
                fmt_specs.type = 0;
                this->write( value != 0 );
            } else if( std::is_same<T, char_type>::value ) {
                format_specs &fmt_specs = *this->specs();
                if( fmt_specs.type && fmt_specs.type != 'c' ) {
                    return ( *this )( static_cast<int>( value ) );
                }
                fmt_specs.sign = sign::none;
                fmt_specs.alt = false;
                fmt_specs.fill[0] = ' ';  // Ignore '0' flag for char types.
                // align::numeric needs to be overwritten here since the '0' flag is
                // ignored for non-numeric types
                if( fmt_specs.align == align::none || fmt_specs.align == align::numeric ) {
                    fmt_specs.align = align::right;
                }
                return base::operator()( value );
            } else {
                return base::operator()( value );
            }
            return this->out();
        }

        template <typename T, FMT_ENABLE_IF( std::is_floating_point<T>::value )>
        iterator operator()( T value ) {
            return base::operator()( value );
        }

        /** Formats a null-terminated C string. */
        iterator operator()( const char *value ) {
            if( value ) {
                base::operator()( value );
            } else if( this->specs()->type == 'p' ) {
                write_null_pointer( char_type() );
            } else {
                this->write( "(null)" );
            }
            return this->out();
        }

        /** Formats a null-terminated wide C string. */
        iterator operator()( const wchar_t *value ) {
            if( value ) {
                base::operator()( value );
            } else if( this->specs()->type == 'p' ) {
                write_null_pointer( char_type() );
            } else {
                this->write( L"(null)" );
            }
            return this->out();
        }

        iterator operator()( basic_string_view<char_type> value ) {
            return base::operator()( value );
        }

        iterator operator()( monostate value ) {
            return base::operator()( value );
        }

        /** Formats a pointer. */
        iterator operator()( const void *value ) {
            if( value ) {
                return base::operator()( value );
            }
            this->specs()->type = 0;
            write_null_pointer( char_type() );
            return this->out();
        }

        /** Formats an argument of a custom (user-defined) type. */
        iterator operator()( typename basic_format_arg<context_type>::handle handle ) {
            handle.format( context_.parse_context(), context_ );
            return this->out();
        }
};

template <typename T> struct printf_formatter {
    printf_formatter() = delete;

    template <typename ParseContext>
    auto parse( ParseContext &ctx ) -> decltype( ctx.begin() ) {
        return ctx.begin();
    }

    template <typename FormatContext>
    auto format( const T &value, FormatContext &ctx ) -> decltype( ctx.out() ) {
        detail::format_value( detail::get_container( ctx.out() ), value );
        return ctx.out();
    }
};

/**
 This template formats data and writes the output through an output iterator.
 */
template <typename OutputIt, typename Char> class basic_printf_context
{
    public:
        /** The character type for the output. */
        using char_type = Char;
        using iterator = OutputIt;
        using format_arg = basic_format_arg<basic_printf_context>;
        using parse_context_type = basic_printf_parse_context<Char>;
        template <typename T> using formatter_type = printf_formatter<T>;

    private:
        using format_specs = basic_format_specs<char_type>;

        OutputIt out_;
        basic_format_args<basic_printf_context> args_;
        parse_context_type parse_ctx_;

        static void parse_flags( format_specs &specs, const Char *&it,
                                 const Char *end );

        // Returns the argument with specified index or, if arg_index is -1, the next
        // argument.
        format_arg get_arg( int arg_index = -1 );

        // Parses argument index, flags and width and returns the argument index.
        int parse_header( const Char *&it, const Char *end, format_specs &specs );

    public:
        /**
         \rst
         Constructs a ``printf_context`` object. References to the arguments are
         stored in the context object so make sure they have appropriate lifetimes.
         \endrst
         */
        basic_printf_context( OutputIt out, basic_string_view<char_type> format_str,
                              basic_format_args<basic_printf_context> args )
            : out_( out ), args_( args ), parse_ctx_( format_str ) {}

        OutputIt out() {
            return out_;
        }
        void advance_to( OutputIt it ) {
            out_ = it;
        }

        detail::locale_ref locale() {
            return {};
        }

        format_arg arg( int id ) const {
            return args_.get( id );
        }

        parse_context_type &parse_context() {
            return parse_ctx_;
        }

        FMT_CONSTEXPR void on_error( const char *message ) {
            parse_ctx_.on_error( message );
        }

        /** Formats stored arguments and writes the output to the range. */
        template <typename ArgFormatter = printf_arg_formatter<OutputIt, Char>>
        OutputIt format();
};

template <typename OutputIt, typename Char>
void basic_printf_context<OutputIt, Char>::parse_flags( format_specs &specs,
        const Char *&it,
        const Char *end )
{
    for( ; it != end; ++it ) {
        switch( *it ) {
            case '-':
                specs.align = align::left;
                break;
            case '+':
                specs.sign = sign::plus;
                break;
            case '0':
                specs.fill[0] = '0';
                break;
            case ' ':
                if( specs.sign != sign::plus ) {
                    specs.sign = sign::space;
                }
                break;
            case '#':
                specs.alt = true;
                break;
            default:
                return;
        }
    }
}

template <typename OutputIt, typename Char>
typename basic_printf_context<OutputIt, Char>::format_arg
basic_printf_context<OutputIt, Char>::get_arg( int arg_index )
{
    if( arg_index < 0 ) {
        arg_index = parse_ctx_.next_arg_id();
    } else {
        parse_ctx_.check_arg_id( --arg_index );
    }
    return detail::get_arg( *this, arg_index );
}

template <typename OutputIt, typename Char>
int basic_printf_context<OutputIt, Char>::parse_header( const Char *&it,
        const Char *end,
        format_specs &specs )
{
    int arg_index = -1;
    char_type c = *it;
    if( c >= '0' && c <= '9' ) {
        // Parse an argument index (if followed by '$') or a width possibly
        // preceded with '0' flag(s).
        detail::error_handler eh;
        int value = parse_nonnegative_int( it, end, eh );
        if( it != end && *it == '$' ) { // value is an argument index
            ++it;
            arg_index = value;
        } else {
            if( c == '0' ) {
                specs.fill[0] = '0';
            }
            if( value != 0 ) {
                // Nonzero value means that we parsed width and don't need to
                // parse it or flags again, so return now.
                specs.width = value;
                return arg_index;
            }
        }
    }
    parse_flags( specs, it, end );
    // Parse width.
    if( it != end ) {
        if( *it >= '0' && *it <= '9' ) {
            detail::error_handler eh;
            specs.width = parse_nonnegative_int( it, end, eh );
        } else if( *it == '*' ) {
            ++it;
            specs.width = static_cast<int>( visit_format_arg(
                                                detail::printf_width_handler<char_type>( specs ), get_arg() ) );
        }
    }
    return arg_index;
}

template <typename OutputIt, typename Char>
template <typename ArgFormatter>
OutputIt basic_printf_context<OutputIt, Char>::format()
{
    auto out = this->out();
    const Char *start = parse_ctx_.begin();
    const Char *end = parse_ctx_.end();
    auto it = start;
    while( it != end ) {
        char_type c = *it++;
        if( c != '%' ) {
            continue;
        }
        if( it != end && *it == c ) {
            out = std::copy( start, it, out );
            start = ++it;
            continue;
        }
        out = std::copy( start, it - 1, out );

        format_specs specs;
        specs.align = align::right;

        // Parse argument index, flags and width.
        int arg_index = parse_header( it, end, specs );
        if( arg_index == 0 ) {
            on_error( "argument not found" );
        }

        // Parse precision.
        if( it != end && *it == '.' ) {
            ++it;
            c = it != end ? *it : 0;
            if( '0' <= c && c <= '9' ) {
                detail::error_handler eh;
                specs.precision = parse_nonnegative_int( it, end, eh );
            } else if( c == '*' ) {
                ++it;
                specs.precision = static_cast<int>(
                                      visit_format_arg( detail::printf_precision_handler(), get_arg() ) );
            } else {
                specs.precision = 0;
            }
        }

        format_arg arg = get_arg( arg_index );
        // For d, i, o, u, x, and X conversion specifiers, if a precision is
        // specified, the '0' flag is ignored
        if( specs.precision >= 0 && arg.is_integral() )
            specs.fill[0] =
                ' ';  // Ignore '0' flag for non-numeric types or if '-' present.
        if( specs.precision >= 0 && arg.type() == detail::type::cstring_type ) {
            auto str = visit_format_arg( detail::get_cstring<Char>(), arg );
            auto str_end = str + specs.precision;
            auto nul = std::find( str, str_end, Char() );
            arg = detail::make_arg<basic_printf_context>( basic_string_view<Char>(
                        str,
                        detail::to_unsigned( nul != str_end ? nul - str : specs.precision ) ) );
        }
        if( specs.alt && visit_format_arg( detail::is_zero_int(), arg ) ) {
            specs.alt = false;
        }
        if( specs.fill[0] == '0' ) {
            if( arg.is_arithmetic() && specs.align != align::left ) {
                specs.align = align::numeric;
            } else {
                specs.fill[0] = ' ';    // Ignore '0' flag for non-numeric types or if '-'
            }
            // flag is also present.
        }

        // Parse length and convert the argument to the required type.
        c = it != end ? *it++ : 0;
        char_type t = it != end ? *it : 0;
        using detail::convert_arg;
        switch( c ) {
            case 'h':
                if( t == 'h' ) {
                    ++it;
                    t = it != end ? *it : 0;
                    convert_arg<signed char>( arg, t );
                } else {
                    convert_arg<short>( arg, t );
                }
                break;
            case 'l':
                if( t == 'l' ) {
                    ++it;
                    t = it != end ? *it : 0;
                    convert_arg<long long>( arg, t );
                } else {
                    convert_arg<long>( arg, t );
                }
                break;
            case 'j':
                convert_arg<intmax_t>( arg, t );
                break;
            case 'z':
                convert_arg<size_t>( arg, t );
                break;
            case 't':
                convert_arg<std::ptrdiff_t>( arg, t );
                break;
            case 'L':
                // printf produces garbage when 'L' is omitted for long double, no
                // need to do the same.
                break;
            default:
                --it;
                convert_arg<void>( arg, c );
        }

        // Parse type.
        if( it == end ) {
            FMT_THROW( format_error( "invalid format string" ) );
        }
        specs.type = static_cast<char>( *it++ );
        if( arg.is_integral() ) {
            // Normalize type.
            switch( specs.type ) {
                case 'i':
                case 'u':
                    specs.type = 'd';
                    break;
                case 'c':
                    visit_format_arg( detail::char_converter<basic_printf_context>( arg ),
                                      arg );
                    break;
            }
        }

        start = it;

        // Format argument.
        out = visit_format_arg( ArgFormatter( out, specs, *this ), arg );
    }
    return std::copy( start, it, out );
}

template <typename Char>
using basic_printf_context_t =
    basic_printf_context<detail::buffer_appender<Char>, Char>;

using printf_context = basic_printf_context_t<char>;
using wprintf_context = basic_printf_context_t<wchar_t>;

using printf_args = basic_format_args<printf_context>;
using wprintf_args = basic_format_args<wprintf_context>;

/**
  \rst
  Constructs an `~fmt::format_arg_store` object that contains references to
  arguments and can be implicitly converted to `~fmt::printf_args`.
  \endrst
 */
template <typename... Args>
inline format_arg_store<printf_context, Args...> make_printf_args(
    const Args &... args )
{
    return {args...};
}

/**
  \rst
  Constructs an `~fmt::format_arg_store` object that contains references to
  arguments and can be implicitly converted to `~fmt::wprintf_args`.
  \endrst
 */
template <typename... Args>
inline format_arg_store<wprintf_context, Args...> make_wprintf_args(
    const Args &... args )
{
    return {args...};
}

template <typename S, typename Char = char_t<S>>
inline std::basic_string<Char> vsprintf(
    const S &format,
    basic_format_args<basic_printf_context_t<type_identity_t<Char>>> args )
{
    basic_memory_buffer<Char> buffer;
    vprintf( buffer, to_string_view( format ), args );
    return to_string( buffer );
}

/**
  \rst
  Formats arguments and returns the result as a string.

  **Example**::

    std::string message = fmt::sprintf("The answer is %d", 42);
  \endrst
*/
template <typename S, typename... Args,
          typename Char = enable_if_t<detail::is_string<S>::value, char_t<S>>>
                                      inline std::basic_string<Char> sprintf( const S &format, const Args &... args )
{
    using context = basic_printf_context_t<Char>;
    return vsprintf( to_string_view( format ), make_format_args<context>( args... ) );
}

template <typename S, typename Char = char_t<S>>
inline int vfprintf(
    std::FILE *f, const S &format,
    basic_format_args<basic_printf_context_t<type_identity_t<Char>>> args )
{
    basic_memory_buffer<Char> buffer;
    vprintf( buffer, to_string_view( format ), args );
    size_t size = buffer.size();
    return std::fwrite( buffer.data(), sizeof( Char ), size, f ) < size
           ? -1
           : static_cast<int>( size );
}

/**
  \rst
  Prints formatted data to the file *f*.

  **Example**::

    fmt::fprintf(stderr, "Don't %s!", "panic");
  \endrst
 */
template <typename S, typename... Args,
          typename Char = enable_if_t<detail::is_string<S>::value, char_t<S>>>
                                      inline int fprintf( std::FILE *f, const S &format, const Args &... args )
{
    using context = basic_printf_context_t<Char>;
    return vfprintf( f, to_string_view( format ),
                     make_format_args<context>( args... ) );
}

template <typename S, typename Char = char_t<S>>
inline int vprintf(
    const S &format,
    basic_format_args<basic_printf_context_t<type_identity_t<Char>>> args )
{
    return vfprintf( stdout, to_string_view( format ), args );
}

/**
  \rst
  Prints formatted data to ``stdout``.

  **Example**::

    fmt::printf("Elapsed time: %.2f seconds", 1.23);
  \endrst
 */
template <typename S, typename... Args,
          FMT_ENABLE_IF( detail::is_string<S>::value )>
inline int printf( const S &format_str, const Args &... args )
{
    using context = basic_printf_context_t<char_t<S>>;
    return vprintf( to_string_view( format_str ),
                    make_format_args<context>( args... ) );
}

template <typename S, typename Char = char_t<S>>
inline int vfprintf(
    std::basic_ostream<Char> &os, const S &format,
    basic_format_args<basic_printf_context_t<type_identity_t<Char>>> args )
{
    basic_memory_buffer<Char> buffer;
    vprintf( buffer, to_string_view( format ), args );
    detail::write_buffer( os, buffer );
    return static_cast<int>( buffer.size() );
}

/** Formats arguments and writes the output to the range. */
template <typename ArgFormatter, typename Char,
          typename Context =
          basic_printf_context<typename ArgFormatter::iterator, Char>>
typename ArgFormatter::iterator vprintf(
    detail::buffer<Char> &out, basic_string_view<Char> format_str,
    basic_format_args<type_identity_t<Context>> args )
{
    typename ArgFormatter::iterator iter( out );
    Context( iter, format_str, args ).template format<ArgFormatter>();
    return iter;
}

/**
  \rst
  Prints formatted data to the stream *os*.

  **Example**::

    fmt::fprintf(cerr, "Don't %s!", "panic");
  \endrst
 */
template <typename S, typename... Args, typename Char = char_t<S>>
inline int fprintf( std::basic_ostream<Char> &os, const S &format_str,
                    const Args &... args )
{
    using context = basic_printf_context_t<Char>;
    return vfprintf( os, to_string_view( format_str ),
                     make_format_args<context>( args... ) );
}
FMT_END_NAMESPACE

#endif  // CATA_SRC_FMTLIB_PRINTF_H