如何最好转换VARIANT_BOOL到C ++的布尔？ [英] How to best convert VARIANT_BOOL to C++ bool?
问题描述
在使用COM布尔值作为在wtypes.h声明的短的VARIANT_BOOL传递。也有predefined值的真正的和的假的：
When using COM boolean values are to be passed as VARIANT_BOOL which is declared in wtypes.h as short. There are also predefined values for true and false:
#define VARIANT_TRUE ((VARIANT_BOOL)-1)
#define VARIANT_FALSE ((VARIANT_BOOL)0)
这是从VARIANT_BOOL转换成C ++的最好办法布尔键入？显而易见的变体是：
Which is the best way to convert from VARIANT_BOOL to C++ bool type? Obvious variants are:
-
与VARIANT_FALSE比较
compare with VARIANT_FALSE
只是投为bool
其他方法可以很容易地创造。
Other ways can be easily invented.
这是做到这一点的最好方法？ - 最可读的，最非标准兼容的，最不容易accidential错误种植和最不容易的问题与移植到64位平台。
Which is the best way to do this - most readable, most standart-compliant, least prone to accidential bugs planting and least prone to issues with porting to 64-bit platforms?
推荐答案
相较于 VARIANT_FALSE 。有很多车code的在那里，错误地通过在C ++布尔真正值（转换为整数值1）函数期待 VARIANT_BOOL 。如果你比较 VARIANT_FALSE ，你仍然会得到正确的期望值。
Compare to VARIANT_FALSE. There is a lot of buggy code out there that mistakenly passes in the C++ bool true value (cast to the integer value 1) to a function expecting VARIANT_BOOL. If you compare to VARIANT_FALSE, you will still get the correct expected value.
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