Subject: [Boost-commit] svn:boost r52577 - trunk/boost/mpl
From: eric_at_[hidden]
Date: 2009-04-23 17:46:31
Author: eric_niebler
Date: 2009-04-23 17:46:30 EDT (Thu, 23 Apr 2009)
New Revision: 52577
URL: http://svn.boost.org/trac/boost/changeset/52577
Log:
isolate implementation-defined behavior in macros for easier portability
Text files modified:
trunk/boost/mpl/string.hpp | 34 ++++++++++++++++++++++++++--------
1 files changed, 26 insertions(+), 8 deletions(-)
Modified: trunk/boost/mpl/string.hpp
==============================================================================
--- trunk/boost/mpl/string.hpp (original)
+++ trunk/boost/mpl/string.hpp 2009-04-23 17:46:30 EDT (Thu, 23 Apr 2009)
@@ -46,10 +46,28 @@
namespace boost { namespace mpl
{
- #define BOOST_MPL_STRING_MAX_PARAMS BOOST_PP_DIV(BOOST_PP_ADD(BOOST_MPL_LIMIT_STRING_SIZE, 3), 4)
+ #define BOOST_MPL_STRING_MAX_PARAMS \
+ BOOST_PP_DIV(BOOST_PP_ADD(BOOST_MPL_LIMIT_STRING_SIZE, 3), 4)
- #define BOOST_MPL_MULTICHAR_LENGTH(c) (std::size_t)((c>0xffffff)+(c>0xffff)+(c>0xff)+1)
- #define BOOST_MPL_MULTICHAR_AT(c,i) (char)(0xff&(c>>(8*(BOOST_MPL_MULTICHAR_LENGTH(c)-(std::size_t)(i)-1))))
+ // Low-level bit-twiddling is done by macros. Any implementation-defined behavior of
+ // multi-character literals should be localized to these macros.
+ #define BOOST_MPL_MULTICHAR_LENGTH(c) \
+ (std::size_t)((c>0xffffff)+(c>0xffff)+(c>0xff)+1)
+
+ #define BOOST_MPL_MULTICHAR_AT(c,i) \
+ (char)(0xff&(c>>(8*(BOOST_MPL_MULTICHAR_LENGTH(c)-(std::size_t)(i)-1))))
+
+ #define BOOST_MPL_MULTICHAR_PUSH_BACK(c,i) \
+ (((c)<<8)|(unsigned char)(i))
+
+ #define BOOST_MPL_MULTICHAR_PUSH_FRONT(c,i) \
+ ((((unsigned char)(i))<<(BOOST_MPL_MULTICHAR_LENGTH(c)*8))|(c))
+
+ #define BOOST_MPL_MULTICHAR_POP_BACK(c) \
+ ((c)>>8)
+
+ #define BOOST_MPL_MULTICHAR_POP_FRONT(c) \
+ (((1<<((BOOST_MPL_MULTICHAR_LENGTH(c)-1)*8))-1)&(c))
struct string_tag;
struct string_iterator_tag;
@@ -173,7 +191,7 @@
BOOST_PP_COMMA_IF(BOOST_PP_DEC(n)) \
(BOOST_PP_CAT(C,BOOST_PP_DEC(n))>0xffffff) \
?BOOST_PP_CAT(C,BOOST_PP_DEC(n)) \
- :(BOOST_PP_CAT(C,BOOST_PP_DEC(n))<<8)|(unsigned char)Value::value \
+ :BOOST_MPL_MULTICHAR_PUSH_BACK(BOOST_PP_CAT(C,BOOST_PP_DEC(n)), Value::value) \
, (BOOST_PP_CAT(C,BOOST_PP_DEC(n))>0xffffff) \
?(char)Value::value \
:0 \
@@ -190,7 +208,7 @@
typedef
mpl::string<
BOOST_PP_ENUM_PARAMS(BOOST_PP_DEC(BOOST_MPL_STRING_MAX_PARAMS), C)
- , (BOOST_PP_CAT(C,BOOST_PP_DEC(BOOST_MPL_STRING_MAX_PARAMS))<<8)|(unsigned char)Value::value
+ , BOOST_MPL_MULTICHAR_PUSH_BACK(BOOST_PP_CAT(C,BOOST_PP_DEC(BOOST_MPL_STRING_MAX_PARAMS)), Value::value)
>
type;
};
@@ -214,7 +232,7 @@
mpl::string< \
BOOST_PP_ENUM_PARAMS_Z(z, BOOST_PP_DEC(n), C) \
BOOST_PP_COMMA_IF(BOOST_PP_DEC(n)) \
- (BOOST_PP_CAT(C,BOOST_PP_DEC(n))>>8) \
+ BOOST_MPL_MULTICHAR_POP_BACK(BOOST_PP_CAT(C,BOOST_PP_DEC(n))) \
> \
type; \
};
@@ -278,7 +296,7 @@
{
typedef
mpl::string<
- ((((unsigned char)Value::value)<<(BOOST_MPL_MULTICHAR_LENGTH(C0)*8))|C0)
+ BOOST_MPL_MULTICHAR_PUSH_FRONT(C0, Value::value)
, BOOST_PP_ENUM_SHIFTED_PARAMS(BOOST_MPL_STRING_MAX_PARAMS, C)
>
type0;
@@ -324,7 +342,7 @@
{
typedef
mpl::string<
- (((1<<((BOOST_MPL_MULTICHAR_LENGTH(C0)-1)*8))-1)&C0)
+ BOOST_MPL_MULTICHAR_POP_FRONT(C0)
, BOOST_PP_ENUM_SHIFTED_PARAMS(BOOST_MPL_STRING_MAX_PARAMS, C)
>
type;