C类模板偏特化类模板偏特化允许为模板参数的子集提供特殊实现。与函数模板只能完全特化不同类模板支持偏特化提供了更大的灵活性。类模板的基本定义提供通用实现。#include#includetemplateclass Pair {T first_;U second_;public:Pair(const T first, const U second) : first_(first), second_(second) {}void display() const {std::cout Generic Pair: first_ , second_ \n;}};void basic_template() {Pair p1(10, 3.14);p1.display();}偏特化为部分模板参数提供特殊实现。templateclass Pair {T first_;T second_;public:Pair(const T first, const T second) : first_(first), second_(second) {}void display() const {std::cout Same type Pair: first_ , second_ \n;}T sum() const {return first_ second_;}};void partial_specialization() {Pair p(10, 20);p.display();std::cout Sum: p.sum() \n;}指针类型的偏特化。templateclass Pair {T* first_;T* second_;public:Pair(T* first, T* second) : first_(first), second_(second) {}void display() const {std::cout Pointer Pair: *first_ , *second_ \n;}};void pointer_specialization() {int x 10, y 20;Pair p(x, y);p.display();}const类型的偏特化。templateclass Container {T value_;public:explicit Container(const T value) : value_(value) {}void modify() {value_ T();std::cout Modified\n;}};templateclass Container {T value_;public:explicit Container(const T value) : value_(value) {}void modify() {std::cout Cannot modify const container\n;}};数组类型的偏特化。templateclass Array {T data_[N];public:T operator[](size_t index) { return data_[index]; }size_t size() const { return N; }};templateclass Array {public:size_t size() const { return 0; }};类型特征使用偏特化实现。templatestruct IsPointer {static constexpr bool value false;};templatestruct IsPointer {static constexpr bool value true;};templatestruct RemovePointer {using type T;};templatestruct RemovePointer {using type T;};void type_traits_example() {std::cout int is pointer: IsPointer::value \n;std::cout int* is pointer: IsPointer::value \n;using Type RemovePointer::type;std::cout Type is int: std::is_same::value \n;}偏特化可以根据模板参数数量进行。templateclass Tuple;templateclass Tuple {public:void display() const {std::cout Empty tuple\n;}};templateclass Tuple {Head head_;Tuple tail_;public:Tuple(const Head head, const Tail... tail): head_(head), tail_(tail...) {}void display() const {std::cout head_ ;tail_.display();}};类模板偏特化是实现类型特征和元编程的重要工具。
