这种初始化和赋值叫什么？

Question

这个我知道

int value1 = 1; // is copy initialization
double value2(2.2); // is direct initialization
char value3 {'c'}; // is uniform initialization
int value4 = {5}; // is initializer list
value4 = 6; // is copy assignment

我很好奇，这个叫什么？

int value5 = (3);
value5 = (4);
value5 = {5};

Answer 1

对于

int value5 = (3);

是copy initialization

T object = other; (1)

1) when a named variable (automatic, static, or thread-local) of a non-reference type T is declared with the initializer consisting of an equals sign followed by an expression.

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对于：

value5 = (4);
value5 = {5};

直接赋值。

Assignment operators

copy assignment operator replaces the contents of the object a with a copy of the contents of b (b is not modified). For class types, this is a special member function, described in copy assignment operator.

For non-class types, copy and move assignment are indistinguishable and are referred to as direct assignment.

Answer 2

int value5 = (3); 和 value5 = (4); 仍然是复制赋值，因为右侧被简单地分别计算为 3 和 4。

另一方面value5 = {5};是复制初始化列表。