std::inplace_vector<T,N>:: resize

将容器大小调整为包含 count 个元素：

• 若 count 等于当前尺寸，则不执行任何操作。
• 若当前尺寸大于 count ，容器将缩减至其前 count 个元素。
• 若当前尺寸小于 count ，则：

参数

复杂度

与当前大小和 count 之间的差值呈线性关系。

异常处理

若因任何原因抛出异常，这些函数将不产生任何效果（ 强异常安全保证 ）。

示例

#include <inplace_vector>
#include <print>
int main()
{
    std::inplace_vector<int, 6> v(6, 9);
    std::println("Initially, v = {}", v);
    v.resize(2);
    std::println("After resize(2), v = {}", v);
    v.resize(4);
    std::println("After resize(4), v = {}", v);
    v.resize(6, -1);
    std::println("After resize(6, -1), v = {}", v);
    try
    {
        std::print("Trying resize(13): ");
        v.resize(13); // throws, because count > N; v is left unchanged
    }
    catch(const std::bad_alloc& ex)
    {
        std::println("ex.what(): {}", ex.what());
    }
    std::println("After exception, v = {}", v);
}

Initially, v = [9, 9, 9, 9, 9, 9]
After resize(2), v = [9, 9]
After resize(4), v = [9, 9, 0, 0]
After resize(6, -1), v = [9, 9, 0, 0, -1, -1]
Trying resize(13): ex.what(): std::bad_alloc
After exception, v = [9, 9, 0, 0, -1, -1]

参见