mirror of
https://github.com/boostorg/config.git
synced 2025-10-31 15:51:51 +01:00
75 lines
2.7 KiB
C++
75 lines
2.7 KiB
C++
// Copyright David Abrahams 2002.
|
|
// Distributed under 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)
|
|
#ifndef WORKAROUND_DWA2002126_HPP
|
|
# define WORKAROUND_DWA2002126_HPP
|
|
|
|
// Compiler/library version workaround macro
|
|
//
|
|
// Usage:
|
|
//
|
|
// #if BOOST_WORKAROUND(BOOST_MSVC, < 1300)
|
|
// // workaround for eVC4 and VC6
|
|
// ... // workaround code here
|
|
// #endif
|
|
//
|
|
// When BOOST_STRICT_CONFIG is defined, expands to 0. Otherwise, the
|
|
// first argument must be undefined or expand to a numeric
|
|
// value. The above expands to:
|
|
//
|
|
// (BOOST_MSVC) != 0 && (BOOST_MSVC) < 1300
|
|
//
|
|
// When used for workarounds that apply to the latest known version
|
|
// and all earlier versions of a compiler, the following convention
|
|
// should be observed:
|
|
//
|
|
// #if BOOST_WORKAROUND(BOOST_MSVC, BOOST_TESTED_AT(1301))
|
|
//
|
|
// The version number in this case corresponds to the last version in
|
|
// which the workaround was known to have been required. When
|
|
// BOOST_DETECT_OUTDATED_WORKAROUNDS is not the defined, the macro
|
|
// BOOST_TESTED_AT(x) expands to "!= 0", which effectively activates
|
|
// the workaround for any version of the compiler. When
|
|
// BOOST_DETECT_OUTDATED_WORKAROUNDS is defined, a compiler warning or
|
|
// error will be issued if the compiler version exceeds the argument
|
|
// to BOOST_TESTED_AT(). This can be used to locate workarounds which
|
|
// may be obsoleted by newer versions.
|
|
|
|
# ifndef BOOST_STRICT_CONFIG
|
|
|
|
# define BOOST_WORKAROUND(symbol, test) \
|
|
((symbol != 0) && (1 % (( (symbol test) ) + 1)))
|
|
// ^ ^ ^ ^
|
|
// The extra level of parenthesis nesting above, along with the
|
|
// BOOST_OPEN_PAREN indirection below, is required to satisfy the
|
|
// broken preprocessor in MWCW 8.3 and earlier.
|
|
//
|
|
// The basic mechanism works as follows:
|
|
// (symbol test) + 1 => if (symbol test) then 2 else 1
|
|
// 1 % ((symbol test) + 1) => if (symbol test) then 1 else 0
|
|
//
|
|
// The complication with % is for cooperation with BOOST_TESTED_AT().
|
|
// When "test" is BOOST_TESTED_AT(x) and
|
|
// BOOST_DETECT_OUTDATED_WORKAROUNDS is #defined,
|
|
//
|
|
// symbol test => if (symbol <= x) then 1 else -1
|
|
// (symbol test) + 1 => if (symbol <= x) then 2 else 0
|
|
// 1 % ((symbol test) + 1) => if (symbol <= x) then 1 else divide-by-zero
|
|
//
|
|
|
|
# ifdef BOOST_DETECT_OUTDATED_WORKAROUNDS
|
|
# define BOOST_OPEN_PAREN (
|
|
# define BOOST_TESTED_AT(value) > value) ?(-1): BOOST_OPEN_PAREN 1
|
|
# else
|
|
# define BOOST_TESTED_AT(value) != ((value)-(value))
|
|
# endif
|
|
|
|
# else
|
|
|
|
# define BOOST_WORKAROUND(symbol, test) 0
|
|
|
|
# endif
|
|
|
|
#endif // WORKAROUND_DWA2002126_HPP
|