RE: C headers and std namespace

["Anthony Williams" <anthony_w dot geo at yahoo dot com>]

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I have a fix to the problem I reported a few days ago regarding the
<cctype> header and 'using namespace std;'

To recap the problem:

With sparc-solaris-2.7 versions of gcc-2.95.2 and libstdc++-2.90.8
snapshot, the following code produces ambiguity errors:

#include <cctype>

using namespace std;
int main()
{
    char a='A';
    if(isdigit(a))
        return 0;
    return 1;
}

ambiguity: isdigit(char) could be ::isdigit(int) or std::isdigit(int)

Fix:

Modify bits/std_cctype.h as follows:

Add #include <bits/stl_config.h> to the top

Change "namespace std{" to "__STL_BEGIN_NAMESPACE"
Change the matching "}" to "__STL_END_NAMESPACE"

Move the "#include_next <ctype.h>" inside the namespace

Remove all the #elif _GLIBCPP_USE_NAMESPACES sections

Here are the diffs:

diff std_cctype.h.orig std_cctype.h
42c42
< # include_next <ctype.h>
- ---
> #include <bits/stl_config.h>
48,51c48
< namespace std 
< {
<   // NB: If not using namespaces, can't have any of these
definitions,
<   // as they will duplicate what's in the global namespace. 
- ---
> __STL_BEGIN_NAMESPACE
52a50,51
> # include_next <ctype.h>
> 
59,61d57
< #elif _GLIBCPP_USE_NAMESPACES 
<   inline int 
<   toupper(int __c) { return ::toupper(__c); }
70,72d65
< #elif _GLIBCPP_USE_NAMESPACES 
<   inline int 
<   tolower(int __c) { return ::tolower(__c); }
81,83d73
< #elif _GLIBCPP_USE_NAMESPACES 
<   inline int 
<   isspace(int __c) { return ::isspace(__c); }
92,94d81
< #elif _GLIBCPP_USE_NAMESPACES 
<   inline int 
<   isprint(int __c) { return ::isprint(__c); }
103,105d89
< #elif _GLIBCPP_USE_NAMESPACES 
<   inline int 
<   iscntrl(int __c) { return ::iscntrl(__c); }
114,116d97
< #elif _GLIBCPP_USE_NAMESPACES 
<   inline int 
<   isupper(int __c) { return ::isupper(__c); }
125,127d105
< #elif _GLIBCPP_USE_NAMESPACES 
<   inline int 
<   islower(int __c) { return ::islower(__c); }
136,138d113
< #elif _GLIBCPP_USE_NAMESPACES 
<   inline int 
<   isalpha(int __c) { return ::isalpha(__c); }
147,149d121
< #elif _GLIBCPP_USE_NAMESPACES 
<   inline int 
<   isdigit(int __c) { return ::isdigit(__c); }
158,160d129
< #elif _GLIBCPP_USE_NAMESPACES 
<   inline int 
<   ispunct(int __c) { return ::ispunct(__c); }
169,171d137
< #elif _GLIBCPP_USE_NAMESPACES 
<   inline int 
<   isxdigit(int __c) { return ::isxdigit(__c); }
180,182d145
< #elif _GLIBCPP_USE_NAMESPACES 
<   inline int 
<   isalnum(int __c) { return ::isalnum(__c); }
191,193d153
< #elif _GLIBCPP_USE_NAMESPACES 
<   inline int 
<   isgraph(int __c) { return ::isgraph(__c); }
196c156
< } // namespace std
- ---
> __STL_END_NAMESPACE


Now, all macros are replaced with inline functions, and everything is
in the std:: namespace (if __STL_BEGIN_NAMESPACE says so)

Anthony

alink@anthonyw.cjb.net -- Questions relating to ALINK
anthony@anthonyw.cjb.net  -- Non-ALINK questions
http://anthonyw.cjb.net/ -- ALINK home page
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