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Fix a bug in preprocessor usage

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[SVN r18231]
This commit is contained in:
Dave Abrahams
2003-04-11 06:56:52 +00:00
parent 56acf9c325
commit 1be04eeec5
1 changed files with 48 additions and 42 deletions
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16
include/boost/operators.hpp
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@ -78,6 +78,7 @@
#include <boost/config.hpp>
#include <boost/iterator.hpp>
#include <boost/preprocessor/seq/cat.hpp>
#if defined(__sgi) && !defined(__GNUC__)
# pragma set woff 1234
@ -152,6 +153,9 @@ struct equality_comparable1 : B
friend bool operator!=(const T& x, const T& y) { return !(x == y); }
};
// A macro which produces "name_2left" from "name".
#define BOOST_OPERATOR2_LEFT(name) BOOST_PP_SEQ_CAT_S(1,(name)(2)(_)(left))
// NRVO-friendly implementation (contributed by Daniel Frey) ---------------//
#if defined(BOOST_HAS_NRVO) || defined(BOOST_FORCE_SYMMETRIC_OPERATORS)
@ -187,7 +191,7 @@ struct NAME##2 : B \
}; \
\
template <class T, class U, class B = ::boost::detail::empty_base> \
struct NAME##2_left : B \
struct BOOST_OPERATOR2_LEFT(NAME) : B \
{ \
friend T operator OP( const U& lhs, const T& rhs ) \
{ T nrv( lhs ); nrv OP##= rhs; return nrv; } \
@ -202,9 +206,10 @@ struct NAME##1 : B \
#else // defined(BOOST_HAS_NRVO) || defined(BOOST_FORCE_SYMMETRIC_OPERATORS)
// For compilers without NRVO the following code is optimal, but not symmetric!
// Note that the implementation of NAME##2_left only looks cool, but doesn't
// provide optimization opportunities to the compiler :)
// For compilers without NRVO the following code is optimal, but not
// symmetric! Note that the implementation of
// BOOST_OPERATOR2_LEFT(NAME) only looks cool, but doesn't provide
// optimization opportunities to the compiler :)
#define BOOST_BINARY_OPERATOR_COMMUTATIVE( NAME, OP ) \
template <class T, class U, class B = ::boost::detail::empty_base> \
@ -228,7 +233,7 @@ struct NAME##2 : B \
}; \
\
template <class T, class U, class B = ::boost::detail::empty_base> \
struct NAME##2_left : B \
struct BOOST_OPERATOR2_LEFT(NAME) : B \
{ \
friend T operator OP( const U& lhs, const T& rhs ) \
{ return T( lhs ) OP##= rhs; } \
@ -253,6 +258,7 @@ BOOST_BINARY_OPERATOR_COMMUTATIVE( orable, | )
#undef BOOST_BINARY_OPERATOR_COMMUTATIVE
#undef BOOST_BINARY_OPERATOR_NON_COMMUTATIVE
#undef BOOST_OPERATOR2_LEFT
// incrementable and decrementable contributed by Jeremy Siek