C++复习——template，template类，memcmp

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本文主要验证：C++模板、模板类、内存比较关键字

MapIndex.h文件：

#ifndef TEMPLATE_CLASS_H#define TEMPLATE_CLASS_Htemplate <class Key, class Value>class MapIndex{private:Key* keys;Value* values;int size = 0;int inuse = -1;~MapIndex();public:MapIndex(int);bool add(Key, Value);Value* get(Key);};#endif

test.cpp文件：

#include<iostream>#include"MapIndex.h"using namespace std;template<class T_SW>void do_sw(T_SW & a, T_SW & b){T_SW c = a + b;a = c - a;b = c - a;}void do_sw(char & a, char & b){cout << "显式具体化" << endl;}template <class Key, class Value>MapIndex<Key, Value>::MapIndex(int _size){this->keys = (Key*)malloc(sizeof(Key)*_size);this->values = (Value*)malloc(sizeof(Value)*_size);this->size = _size;}template <class Key, class Value>MapIndex<Key, Value>::~MapIndex(){free(this->keys);free(this->values);this->size = 0;}template <class Key, class Value>bool MapIndex<Key, Value>::add(Key _key, Value _value){if ((this->inuse + 1) >= this->size){this->inuse = this->size - 1;return false;}++(this->inuse);this->keys[this->inuse] = _key;this->values[this->inuse] = _value;return true;}template <class Key, class Value>Value* MapIndex<Key, Value>::get(Key _key){for (int i = 0; i <= this->inuse; i++){if (memcmp(&(this->keys[i]), &_key, sizeof(Key)) == 0){return &this->values[i];}}return NULL;}int main(int argc, char *argv[]){int i_a = 1;int i_b = 2;cout << "i_a is " << i_a << " i_b is " << i_b << endl;do_sw(i_a, i_b);cout << "i_a is " << i_a << " i_b is " << i_b << endl;//------------------------------------------------------double d_a = 1.1;double d_b = 2.2;cout << "d_a is " << d_a << " d_b is " << d_b << endl;do_sw(d_a, d_b);cout << "d_a is " << d_a << " d_b is " << d_b << endl;//------------------------------------------------------char c_a = 'a';char c_b = 'b';cout << "c_a is " << c_a << " c_b is " << c_b << endl;do_sw(c_a, c_b);cout << "c_a is " << c_a << " c_b is " << c_b << endl;//------------------------------------------------------int* a = new int(5);a[2] = 5;int* b = &a[2];cout << *b << endl;cout << memcmp(a, b, sizeof(int)) << endl;//------------------------------------------------------MapIndex<char, int>* list = new MapIndex<char, int>(2);list->add('y', 1);list->add('g', 2);cout << *list->get('g') << endl;//------------------------------------------------------char end;cin >> end;}

运行结果：

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