Added is_macro_defined() as described in the docs.

[SVN r37148]

ChangeLog

@@ -180,6 +180,9 @@ Boost V1.34.0
   generation of a #line directive.
 - Worked around a linker issue for the True64/CXX compiler, complaining about
   multiple defined symbols when using the flex_string class.
+- Added the is_macro_defined(name) function to the context object as described 
+  in the documentation. This function is usable with any string type compatible 
+  with std::string.
   
 Sat Feb 18 2005
 - Version 1.2.3

include/boost/wave/cpp_context.hpp

@@ -190,6 +190,9 @@ public:
             bool is_predefined = false)
         { return macros.add_macro(name, has_params, parameters, definition, 
             is_predefined); }
+    template <typename StringT>
+    bool is_defined_macro(StringT const &str) 
+        { return macros.is_defined(str.begin(), str.end()); }
     template <typename IteratorT2>
     bool is_defined_macro(IteratorT2 const &begin, IteratorT2 const &end) 
         { return macros.is_defined(begin, end); }
@@ -214,12 +217,13 @@ public:
     void reset_macro_definitions() 
         { macros.reset_macromap(); macros.init_predefined_macros(); }
 
-// get the pp-iterator version information 
+// get the Wave version information 
     static std::string get_version()  
         { return boost::wave::util::predefined_macros::get_fullversion(false); }
     static std::string get_version_string()  
         { return boost::wave::util::predefined_macros::get_versionstr(false); }
 
+// access current language options
     void set_language(boost::wave::language_support language_,
                       bool reset_macros = true) 
     { 
@@ -285,7 +289,7 @@ protected:
 //  expand_tokensequence(): 
 //      expands all macros contained in a given token sequence, handles '##' 
 //      and '#' pp operators and re-scans the resulting sequence 
-//      (essentially preprocesses the token sequence).
+//      (essentially pre-processes the token sequence).
 //
 //      The expand_undefined parameter is true during macro expansion inside
 //      a C++ expression given for a #if or #elif statement. 

include/boost/wave/util/cpp_macromap.hpp

@@ -375,7 +375,7 @@ token_id id = token_id(*begin);
     }
 
 IteratorT it = begin;
-string_type name ((*it).get_value());
+string_type name ((*it).get_value().c_str());
 typename defined_macros_type::iterator cit(current_macros -> find(name));
 
     if (++it != end) {