Imported and modified some sources from Boost (http://www.boost.org)

git-svn-id: https://svn.code.sf.net/p/nsis/code/NSIS/trunk@3734 212acab6-be3b-0410-9dea-997c60f758d6

Source/boost/detail/workaround.hpp

@@ -0,0 +1,74 @@
+// Copyright David Abrahams 2002. Permission to copy, use,
+// modify, sell and distribute this software is granted provided this
+// copyright notice appears in all copies. This software is provided
+// "as is" without express or implied warranty, and with no claim as
+// to its suitability for any purpose.
+#ifndef WORKAROUND_DWA2002126_HPP
+# define WORKAROUND_DWA2002126_HPP
+
+// Compiler/library version workaround macro
+//
+// Usage:
+//
+//     #if BOOST_WORKAROUND(BOOST_MSVC, <= 1200)
+//        ... // 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) <= 1200
+//
+// 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