objective-c - 什么是_Complex？

Question

阅读 Objective-C type encodings documentation (GCC 和 Apple 的页面在某种程度上是互补的)，我偶然发现了 _Complex 关键字。我从未听说过它，当我尝试查找它时，我发现大量结果都在谈论它的错误使用，但从未听说过它真正做了什么。

什么是_Complex，它是如何工作的？

Answer 1

一种复数类型，看起来它使用实部的一半位宽和虚部的一半位宽:

_Complex double x; declares x as a variable whose real part and imaginary part are both of type double. _Complex short int y; declares y to have real and imaginary parts of type short int; this is not likely to be useful, but it shows that the set of complex types is complete.

关于“EXC_BAD_ACCESS _Complex 双返回”的帖子

• http://hintsforums.macworld.com/showthread.php?t=92768
• http://developer.apple.com/library/mac/#documentation/DeveloperTools/gcc-4.0.1/gcc/Complex.html