布尔的C ++短路 [英] C++ short-circuiting of booleans

问题描述

我是c ++的新手，我很好奇编译器如何处理boolean的延迟评估。例如，

I'm new to c++ and am curious how the compiler handles lazy evaluation of booleans. For example,

if(A == 1 || B == 2){...}

如果A等于1，是B == 2部分曾评估过吗？

If A does equal 1, is the B==2 part ever evaluated?

推荐答案

不， B == 2 零件不评估。这称为短期评估。

No, the B==2 part is not evaluated. This is called short-circuit evaluation.

修改：作为 Robert C. Cartaino正确地指出，如果逻辑运算符过载，则不会发生短路评估（已经说过，为什么有人会超载逻辑运算符超过我）。

As Robert C. Cartaino rightly points out, if the logical operator is overloaded, short-circuit evaluation does not take place (that having been said, why someone would overload a logical operator is beyond me).

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