cppreference Direct initialization

NOTE:

1、这种是最容易理解的

2、它和value initialization非常类似，不同在于它是带参的

T object ( arg ); T object ( arg1, arg2, ... );
T object { arg };
T ( other ) T ( arg1, arg2, ... )		functional cast
static_cast< T >( other )		explicit conversion
new T(args, ...)
Class::Class() : member(args, ...) { ... }
[arg](){ ... }

Effect

NOTE:

1、目前的认知是，对应的constructor会被调用

Notes

Constructor

Direct-initialization is more permissive(自由) than copy-initialization: copy-initialization only considers non-explicit constructors and non-explicit user-defined conversion functions, while direct-initialization considers all constructors and all user-defined conversion functions.

NOTE:

1、上述 conversion functions 其实就是"user-defined conversion function"

Syntax ambiguity

NOTE:

1、这部分内容放到了 Syntax-ambiguity-in-initialization-with-round-parenthese 章节