契约支持 (C++26) - cppreference.com 语言支持 库功能特性测试宏 (C++20) 类型支持（基本类型、RTTI） 程序工具 可变参数函数 is_constant_evaluated(C++20) is_within_lifetime(C++26) initializer_list(C++11) source_location(C++20) 协程支持 (C++20) 契约支持 (C++26) 三路比较 three_way_comparablethree_way_comparable_with(C++20)(C++20) strong_ordering(C++20) weak_ordering(C++20) partial_ordering(C++20) common_comparison_category(C++20) compare_three_way_result(C++20) compare_three_way(C++20) strong_order(C++20) weak_order(C++20) partial_order(C++20) compare_strong_order_fallback(C++20) compare_weak_order_fallback(C++20) compare_partial_order_fallback(C++20) is_eqis_ltis_lteq(C++20)(C++20)(C++20) is_neqis_gtis_gteq(C++20)(C++20)(C++20) 通用工具 函数对象 位操纵 (C++20) bitset hash(C++11) 关系运算符 (C++20 弃用) rel_ops::operator!=rel_ops::operator>rel_ops::operator<=rel_ops::operator>= 整数比较函数 cmp_equalcmp_lesscmp_less_than(C++20)(C++20)(C++20) cmp_not_equalcmp_greatercmp_greater_than(C++20)(C++20)(C++20) in_range(C++20) 交换与类型运算 swap ranges::swap(C++20) exchange(C++14) declval(C++11) to_underlying(C++23) forward(C++11) forward_like(C++23) move(C++11) move_if_noexcept(C++11) as_const(C++17) 常用词汇类型 pair tuple(C++11) optional(C++17) any(C++17) variant(C++17) tuple_size(C++11) tuple_element(C++11) apply(C++17) make_from_tuple(C++17) expected(C++23)