我需要实现模板功能的特殊化，该功能执行查找两个C样式字符串中较小的字符串的功能

问题描述

我已经编写了这段代码来实现上述问题的模板专业化，但是代码不正确，因为它是从我在顶部编写的模板函数返回的值，而没有检查我在下面编写的实际模板专业化函数寻找它 两个C风格的字符串中的较小者。所有测试用例无论对还是错都通过了，请帮助我解决此问题。 这是我的代码

代码：

#include "pch.h"
#include<iostream>
using namespace std;

template<typename T>
T smaller(T a,T b) {
    if (a < b)
        return a;
    return b;
}
//template<typename T>
//T smaller(T a,T b,T c)
//{
//  if (a < b && a < c)
//      return a;
//  else if (b < c && b < a)
//      return b;
//  else if (c < a && c < b)
//      return c;
//  
//}
template <>
const char* smaller<const char *>(const char *a,const char *b)
{
    //int strcmp ( const char * str1,const char * str2 );
    if (strcmp(a,b) == 0)
        return "0";
    else if (strcmp(a,b) > 0)
        return b;
    else if (strcmp(a,b) < 0)
        return a;
    
}
//TEST(smaller,TestName) {
//  EXPECT_EQ('B',smaller('a','B'));
//  EXPECT_EQ(12,smaller(15,12));
//  EXPECT_EQ(33.1,smaller(33.1,44.2));
//  //EXPECT_TRUE(true);
//}

//TEST(smaller,TestName_2) {
//  EXPECT_EQ('B','B','c'));
//  EXPECT_EQ(12,12,13));
//  EXPECT_EQ(33.1,44.2,44.5));
//  //EXPECT_TRUE(true);
//}

TEST(smaller,TestName_3) {
    string a = "ABC";
    string b = "DEF";
    EXPECT_EQ("ABC",smaller(a,b));
    string c = "AB";
    string d = "DE";
    EXPECT_EQ("AB",smaller(c,d));
    string e = "Ba";
    string f = "Dd";
    EXPECT_EQ("Ba",smaller(e,f));
}

解决方法

就像以前一样实现它

由于我不知道TEST是什么，因此我在其他版本中进行了更改。

#include <cassert>
#include <cstring>
#include <iostream>
using namespace std;

template <typename T>
T smaller(T a,T b) {
  if (a < b) return a;
  return b;
}

template <>
const char *smaller<const char *>(const char *a,const char *b) {
  int ans = strcmp(a,b);
  if (ans == 0) {
    return "0";
  }
  return ans > 0 ? b : a;
}

template <typename T>
void EXPECT_EQ(T ans,T give) {
  assert(ans == give);
}

template <>
void EXPECT_EQ(const char *ans,const char *give) {
  assert(!strcmp(ans,give));
}

int main() {
  const char *a = "ABC";
  const char *b = "DEF";
  EXPECT_EQ("ABC",smaller(a,b));
  const char *c = "AB";
  const char *d = "DE";
  EXPECT_EQ("AB",smaller(c,d));
  const char *e = "Ba";
  const char *f = "Dd";
  EXPECT_EQ("Ba",smaller(e,f));
}

,

it works for me. 

#include"pch.h"
#include <cassert>
#include <cstring>
#include <iostream>
using namespace std;

template <typename T>
T smaller(T a,T b) {
    if (a < b) return a;
    return b;
}

template <>
const char* smaller<const char*>(const char* a,const char* b) {
    int ans = strcmp(a,b);
    if (ans == 0) {
        return "0";
    }
    return ans > 0 ? b : a;
}

//template <typename T>
//void EXPECT_EQ(T ans,T give) {
//    assert(ans == give);
//}
//
//template <>
//void EXPECT_EQ(const char* ans,const char* give) {
//    assert(!strcmp(ans,give));
//}

TEST(smaller,TestName_3) {
    const char* a = "ABC";
    const char* b = "DEF";
    const char* aa = smaller(a,b);
    EXPECT_EQ(a,aa);
    const char* c = "AB";
    const char* d = "DE";
    const char* dd = smaller(c,d);
    EXPECT_EQ(c,dd);
    const char* e = "Ba";
    const char* f = "Dd";
    const char* ff = smaller(e,f);
    EXPECT_EQ(e,ff);
}