boost/format/detail/compat_workarounds.hpp

// ----------------------------------------------------------------------------
//  compat_workarounds : general framework for non-conformance workarounds
// ----------------------------------------------------------------------------
//  Copyright Samuel Krempp 2003. Use, modification, and distribution are
//  subject to the Boost Software License, Version 1.0. (See accompanying
//  file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
// see http://www.boost.org/libs/format for library home page
// ----------------------------------------------------------------------------
//  this file defines  wrapper classes to hide non-conforming 
// std::char_traits<>  and std::allocator<> traits
//  and Includes : config_macros.hpp (defines config macros
//  and compiler-specific switches)
// Non-conformant Std-libs fail to supply conformant traits (std::char_traits,
//  std::allocator) and/or  the std::string doesnt support them.
// We don't want to have hundreds of #ifdef workarounds, so we define 
// replacement traits.
// But both char_traits and allocator traits are visible in the interface, 
// (inside the final string type),  thus we need to keep both 
// the replacement type (typedefed to 'compatible_type') for real use,
// and the original stdlib type (typedef to 'type_for_string') for interface
//  visibility. This is what Compat* classes do (as well as be transparent 
// when good allocator and char traits are present)
#ifndef BOOST_FORMAT_COMPAT_WORKAROUNDS_HPP
#define BOOST_FORMAT_COMPAT_WORKAROUNDS_HPP
namespace boost {
    namespace io {
        // gcc-2.95 char traits (non-conformantly named string_char_traits) 
        // lack several functions so we extend them in a replacement class.
        template<class Tr>
        class CompatTraits; 
        // std::allocator<Ch> in gcc-2.95 is ok, but basic_string only works 
        // with plain 'std::alloc' still, alt_stringbuf requires a functionnal
        // alloc template argument, so we need a replacement allocator
        template<class Alloc>
        class CompatAlloc; 
    } // N.S. io
}// N.S. boost
#include <boost/format/detail/config_macros.hpp>
   // sets-up macros and load compiler-specific workarounds headers.
#if !defined(BOOST_FORMAT_STREAMBUF_DEFINED)
// workarounds-gcc-2.95 might have defined own streambuf
#include <streambuf>
#endif
#if !defined(BOOST_FORMAT_OSTREAM_DEFINED)
// workarounds-gcc-2.95 might already have included <iostream>
#include <ostream>
#endif
namespace boost {
    namespace io {
        // **** CompatTraits general definitions : ----------------------------
        template<class Tr>
        class CompatTraits
        {        // general case : be transparent
        public:
            typedef Tr  compatible_type;
        };
        // **** CompatAlloc general definitions : -----------------------------
        template<class Alloc>
        class CompatAlloc
        {        // general case : be transparent
        public:
            typedef Alloc  compatible_type;
        };
    } //N.S. io
} // N.S. boost
#endif // include guard