numeric_limits::is_signed

如果类型的有符号的表示形式，测试。

static const bool is_signed = false;

返回值

true，如果该类型的有符号的表示形式; false，如果没有。

备注

该成员存储为true的有符号的表示形式，是所有预定义的浮点和带符号整数类型的用例的类型。

示例

// numeric_limits_is_signaled.cpp
// compile with: /EHsc
#include <iostream>
#include <limits>

using namespace std;

int main( )
{
   cout << "Whether float objects have a signed representation: "
        << numeric_limits<float>::is_signed
        << endl;
   cout << "Whether double objects have a signed representation: "
        << numeric_limits<double>::is_signed
        << endl;
   cout << "Whether signed char objects have a signed representation: "
        << numeric_limits<signed char>::is_signed
        << endl;
   cout << "Whether unsigned char objects have a signed representation: "
        << numeric_limits<unsigned char>::is_signed
        << endl;
}

要求

标头: <limits>

命名空间: std

请参见

参考

strstreambuf Class