编译错误： call of overloaded ‘isnan(double&)’ is ambiguous isnan(x);

最新推荐文章于 2024-02-14 12:07:44 发布

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最新推荐文章于 2024-02-14 12:07:44 发布 · 3.3k 阅读

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#C++ #C11

在C++11环境下，使用`isnan(x)`会导致编译错误，原因是libstdC++的一个bug。解决此问题的方法是通过明确指定作用域，如`::isnan(x)`或`std::isnan(x)`。该问题的更多细节及解决方案可参考GCC Bugzilla和Stack Overflow的相关讨论。

C++11编译报错

测试

#include <stdlib.h>
#include <cmath>
#include <stdio.h>

using namespace std;

int main(int argc, char** argv)
{
    double number = 0;
    if (isnan(number))
    {
        printf("Nan\n");
    }
    return 0;
}

以上代码使用C++11编译时候会产生编译错误

test.cc: In function ‘int main()’:
test.cc:6:10: error: call of overloaded ‘isnan(double&)’ is ambiguous
   isnan(x);
          ^
test.cc:6:10: note: candidates are:
In file included from /usr/include/features.h:374:0,
                 from /usr/include/x86_64-linux-gnu/c++/4.8/bits/os_defines.h:39,
                 from /usr/include/x86_64-linux-gnu/c++/4.8/bits/c++config.h:426,
                 from /usr/include/c++/4.8/cmath:41,
                 from test.cc:1:
/usr/include/x86_64-linux-gnu/bits/mathcalls.h:234:1: note: int isnan(double)
 __MATHDECL_1 (int,isnan,, (_Mdouble_ __value)) __attribute__ ((__const__));
 ^
In file inclu