What is the difference between a reinterpret_cast and a C-style cast? [duplicate]

问题

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When should static_cast, dynamic_cast, const_cast and reinterpret_cast be used? (8 answers)

Closed 5 years ago.

What is the difference between :

double x = 10.3;
int y;
y = (int) x;    // c-like cast notation

And :

double x = 10.3;
int y;
y = reinterpret_cast<int>(x)   

回答1:

A C-style cast can be any of the following types of casts:

• const_cast
• static_cast
• static_cast followed by a const_cast
• reinterpret_cast
• reinterpret_cast followed by a const_cast

the first one from that list that can be done is the what the C-style cast will perform (from C++03 5.4: "Explicit type conversion (cast notation)"

So for your example:

double x = 10.3;
int y;
y = (int) x;

the type of cast used would be a static_cast.

And y = reinterpret_cast<int>(x); won't compile.

来源：https://stackoverflow.com/questions/22999529/what-is-the-difference-between-a-reinterpret-cast-and-a-c-style-cast