C++重载的时候会优先匹配非模块函数-白红宇

C++重载的时候会优先匹配非模块函数

阅读量：6373 次

发布时间：2019-06-23

本文共 4036 字，大约阅读时间需要 13 分钟。

发现当重载函数足够多的时候,

出现可以符合非模块函数,及模块函数都可匹配的时候,

GCC好像会优先匹配非模块函数.

见下面代码

#include 
     
      #include 
      
       #include 
       
        #include 
        
         using namespace std;int max(const int n1, const int n2){    return n1 > n2 ? n1 : n2;}float max( const float f1, const float f2){    return f1 > f2 ? f1 : f2;}string max(const string str1, const  string str2){    return str1 > str2 ? str1 : str2;}#if 0int max(const vector
         
          & vec){    return *max_element(vec.begin(), vec.end());}float max(const vector
          
           & vec){ return *max_element(vec.begin(), vec.end());}string max(const vector
           
            & vec){ return *max_element(vec.begin(), vec.end());}int max(const int* array, int size){ int int_max = numeric_limits
            
             ::min(); for(int i = 0; i < size; ++i) { int_max = max(int_max, array[i]); } return int_max;}float max(const float* array, int size){ float float_max = numeric_limits
             
              ::min(); for(int i = 0; i < size; ++i) { float_max = max(float_max, array[i]); } return float_max;}string max(const string* array, int size){ return *max_element(array, array + size);}#endiftemplate 
              
               T max(const vector
               
                & vec) { cout << "invoke" <
                
                 T max(const T* array, int size){ return *max_element(array, array + size);}int main(int argc, const char *argv[]){ cout << "test overload max" << endl; int n1 = 3; int n2 = 9; float f1 = 3.14; float f2 = 98.44; string str1 = "s1"; string str2 = "abc"; cout << "max int (" << n1 << " " << n2 << " )" << max(n1, n2) << endl << " max float (" << f1 << " " << f2 << " ) " << max(f1, f2) << endl << "max string ( " << str1 << " " << str2 << " ) " << max(str1, str2) << endl; int int_array[] = { 33,444,5,322,124,55,3436}; vector
                 
                   int_vec (int_array, int_array + sizeof(int_array)/ sizeof(int)); cout << " the max number of the int vector is : " << max(int_vec) << endl; float f_array[] = { 34.24, 4324.43, 9999.43, 556.34}; vector
                  
                    f_vec (f_array, f_array + sizeof(f_array) / sizeof(float)); cout << " the max number of the float vector is : " << max(f_vec) << endl; string str_array[] = { "boog", "gogod", "zero", "loe", "abcdasdfas", "asfdksdljjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjj"}; vector
                   
                     str_vec (str_array, str_array + sizeof(str_array) / sizeof(string)); cout << " the max number of the string vector is : " << max(str_vec) << endl;#if 1 cout << "the max number of the int array is :" << max( int_array, sizeof(int_array)/ sizeof(int)) <