isblank() is not recognized

Question

It seems that the isblank() function of the cctype header does not recognized by the gcc compiler. I use code blocks and I get:

error: 'isblank' was not declared in this scope

I checked the gcc cctype header and found the following lines:

   81 #ifdef __GXX_EXPERIMENTAL_CXX0X__
   82 
   83 #ifdef _GLIBCXX_USE_C99_CTYPE_TR1
   84 
   85 #undef isblank
   86 
   87 namespace std
   88 {
   89   using ::isblank;
   90 } // namespace std
   91 
   92 #endif // _GLIBCXX_USE_C99_CTYPE_TR1
   93 
   94 #endif // __GXX_EXPERIMENTAL_CXX0X__
   95 
   96 #endif

How can I get isblank() to work? and what are these lines basically about?

UPDATE

My code:

#include <iostream>
#include <cctype>

using namespace std;

int main()
{
    char ch;

    cout << "\n\n\n Enter a character:  ";
    cin >> ch;

    if (isblank(ch))
        cout << "\n blank characters.";

    cout << "\n\n\n";
}

code blocks version: 16.01 GCC/G++ compiler and GDB debugger from TDM-GCC (version 4.9.2, 32 bit, SJLJ).

What are your `g++` compile options? This seems apropos: http://stackoverflow.com/questions/2958398/gnu-c-how-to-check-when-std-c0x-is-in-effect — Andrew Henle, Mar 19 '17 at 13:32
Also, maybe specify your g++ version (run `g++ -dumpversion`) and codeblocks version; this problem seems version-dependent. — anatolyg, Mar 19 '17 at 13:39

Shadi · Accepted Answer · 2017-05-04T23:54:18.283

2

OK,

Thanks all,

I get it to work by clearing the checked compiler flag:

settings -> compiler settings -> compiler flags -> -std=c++14h

However, I am sure this will affect some other programs. I remember I set this flag because some other features had not worked without it.

Using other compilers is another option as noted in the comments like MinGW64 or MSVC++.

This link could be useful to read:

Thanks again.

edited May 04 '17 at 23:54

answered Mar 19 '17 at 19:56

Shadi

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Consider upgrading your compiler, e.g. you can use the latest version of mingw-w64 which does not have the problem. 4.9.2 is quite old now. – M.M Mar 19 '17 at 20:01

isblank() is not recognized

1 Answers1