c++：定义一个求绝对值函数的模板,调用它分别求整数,单浮点数何双浮点数的绝对值

#include
int add(int x){return x>0?x:-x;}
float add(float x){return x>0?x:-x;}
double add(double x){return x>0?x:-x;}
void main()
{int a; float b; double c;
cout