std::queue<T,Container>:: empty
From cppreference.net
C++
Containers library
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(C++26)
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(C++26)
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(C++11)
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(C++11)
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(C++11)
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(C++11)
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(C++11)
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(C++23)
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(C++23)
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(C++23)
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(C++23)
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std::queue
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queue::empty
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(C++23)
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(C++11)
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| Deduction guides (C++17) |
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bool
empty
(
)
const
;
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检查底层容器是否为空。等价于：
return
c
.
empty
(
)
。
目录 |
参数
(无)
返回值
如果底层容器为空则为 true ，否则为 false 。
复杂度
常量。
示例
运行此代码
#include <cassert> #include <queue> int main() { std::queue<int> queue; assert(queue.empty()); queue.push(42); assert(!queue.empty()); queue.pop(); assert(queue.empty()); }
参见
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返回元素数量
(公开成员函数) |
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(C++17)
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检查容器是否为空
(函数模板) |