我如何在C ++中写一个短文字？ [英] How do I write a short literal in C++?

问题描述

非常基本的问题：我如何在C ++中写一个 short 文字？

Very basic question: how do I write a short literal in C++?

• 2 是 int


• 2U 是 unsigned int


• 2L 是长


• 2LL 是长长


• 2.0f 是 float


• 2.0 c> double


• '\2' code>。

• 2 is an int
• 2U is an unsigned int
• 2L is a long
• 2LL is a long long
• 2.0f is a float
• 2.0 is a double
• '\2' is a char.

但是我如何写一个 short ？我尝试了 2S 但是给出了编译器警告。

But how would I write a short literal? I tried 2S but that gives a compiler warning.

推荐答案

((short)2)

，更多的是casted-int，但是行为是一样的，我认为没有直接的方法。

Yeah, it's not strictly a short literal, more of a casted-int, but the behaviour is the same and I think there isn't a direct way of doing it.

这是我一直在做，因为我找不到任何东西。我猜想编译器会聪明地编译这个，就像它是一个简短的字面量（即，它不会实际分配一个int，然后投射它每次）。

That's what I've been doing because I couldn't find anything about it. I would guess that the compiler would be smart enough to compile this as if it's a short literal (i.e. it wouldn't actually allocate an int and then cast it every time).

下面说明你应该担心多少：

The following illustrates how much you should worry about this:

a = 2L;
b = 2.0;
c = (short)2;
d = '\2';

Compile - > disassemble - >

Compile -> disassemble ->

movl    $2, _a
movl    $2, _b
movl    $2, _c
movl    $2, _d

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