vector<bool>::reference::operator=

将布尔值赋给一个位,或将引用的元素所保存的值赋给一个位。

reference& operator=(
   const reference& Right
);
reference& operator=(
   bool Val
);

参数

  • Right
    要将值赋给位的元素引用。

  • Val
    要赋给位的布尔值。

示例

// vector_bool_ref_op_assign.cpp
// compile with: /EHsc
#include <vector>
#include <iostream>
#include <string>

using namespace std;

template <typename C> void print(const string& s, const C& c) {
    cout << s;

    for (const auto& e : c) {
        cout << e << " ";
    }

    cout << endl;
}

int main()
{
    cout << boolalpha;

    vector<bool> vb = { true, false, false, true, true };

    print("The vector is: ", vb);

    // Invoke vector<bool>::reference::operator=()
    vector<bool>::reference refelem1 = vb[0];
    vector<bool>::reference refelem2 = vb[1];
    vector<bool>::reference refelem3 = vb[2];

    bool b1 = refelem1;
    bool b2 = refelem2;
    bool b3 = refelem3;
    cout << "The original value of the 1st element stored in a bool: " << b1 << endl;
    cout << "The original value of the 2nd element stored in a bool: " << b2 << endl;
    cout << "The original value of the 3rd element stored in a bool: " << b3 << endl;
    cout << endl;

    refelem2 = refelem1;

    print("The vector after assigning refelem1 to refelem2 is now: ", vb);

    refelem3 = true;

    print("The vector after assigning false to refelem1 is now: ", vb);

    // The initial values are still stored in the bool variables and remained unchanged
    cout << "The original value of the 1st element still stored in a bool: " << b1 << endl;
    cout << "The original value of the 2nd element still stored in a bool: " << b2 << endl;
    cout << "The original value of the 3rd element still stored in a bool: " << b3 << endl;
    cout << endl;
}

Output

The vector is: true false false true true
The original value of the 1st element stored in a bool: true
The original value of the 2nd element stored in a bool: false
The original value of the 3rd element stored in a bool: false

The vector after assigning refelem1 to refelem2 is now: true true false true true
The vector after assigning false to refelem1 is now: true true true true true
The original value of the 1st element still stored in a bool: true
The original value of the 2nd element still stored in a bool: false
The original value of the 3rd element still stored in a bool: false

要求

标头:<vector>

命名空间: std

请参见

参考

vector<bool>::reference 类

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