std::ranges::common_view<V>::size
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constexpr auto size() requires ranges::sized_range<V>;
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(1) | (C++20 起) |
constexpr auto size() const requires ranges::sized_range<const V>;
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(2) | (C++20 起) |
返回元素数量。等价于 return ranges::size(base_);。
返回值
元素数量。
示例
运行此代码
#include <ranges> #include <string_view> int main() { constexpr static auto v1 = {1, 2, 3, 4, 5}; constexpr auto common1{v1 | std::views::common}; static_assert(common1.size() == 5); constexpr auto take3{v1 | std::views::reverse | std::views::take(3)}; constexpr auto common2{take3 | std::views::common}; static_assert(common2.size() == 3); using namespace std::literals; constexpr static auto v2 = {"∧"sv, "∨"sv, "∃"sv, "∀"sv}; static_assert(std::ranges::views::common(v2).size() == 4); }
参见
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(C++20)
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返回等于范围大小的整数值
(定制点对象) |
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(C++20)
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返回等于范围大小的有符号整数值
(定制点对象) |