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@JesseChisholm, did you check your C++11 version? I cannot make it work on GCC 4.8.1, 4.9.1, 5.3.0. It says {{missing binary operator before token "("}} on {{#if 0 == c_strmp/*here*/( USER, QUEEN )}}

Dmitriy Elisov
– Dmitriy Elisov

2016-07-20 16:53:53 +00:00
Commented Jul 20, 2016 at 16:53
3

@JesseChisholm So I managed to compile your C++11 example if I change #if 0 == c_strcmp( USER, JACK ) to constexpr int comp1 = c_strcmp( USER, JACK ); #if 0 == comp1

Dmitriy Elisov
– Dmitriy Elisov

2016-07-20 17:12:24 +00:00
Commented Jul 20, 2016 at 17:12
4

@JesseChisholm, hmm, still no luck. Any constexpr variable equals zero in #if.Your example works only because USER is JACK. If USER was QUEEN, it would say USER IS QUEEN and USER_VS IS QUEEN

Dmitriy Elisov
– Dmitriy Elisov

2016-07-20 19:31:31 +00:00
Commented Jul 20, 2016 at 19:31
14

This c++11 part of this answer is wrong. You can't call functions (even constexpr) from preprocessor directives.

interjay
– interjay

2018-04-29 12:49:25 +00:00
Commented Apr 29, 2018 at 12:49
13

This flat-out wrong answer has already misled someone who referenced it. You can't call a constexpr function from the preprocessor; constexpr isn't even recognized as a keyword until translation phase 7. Preprocessing is done in translation phase 4.

H Walters
– H Walters

2018-04-29 17:09:18 +00:00
Commented Apr 29, 2018 at 17:09

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