diff options
| author | usa <usa@b2dd03c8-39d4-4d8f-98ff-823fe69b080e> | 2018-07-30 13:57:35 +0000 |
|---|---|---|
| committer | usa <usa@b2dd03c8-39d4-4d8f-98ff-823fe69b080e> | 2018-07-30 13:57:35 +0000 |
| commit | b6ab48d8b1e90a095388598de95d9116b7f7c3a2 (patch) | |
| tree | 6064c746b962e1ea6cd9621f1196cc7f334d45a7 /include | |
| parent | 7367d5db54d88ad558e94a5e539e58d564454e1a (diff) | |
merge revision(s) 63571,63572: [Backport #14816]
`int isnan(double)` is a POSIXism
- `isnan` is something relatively new. We need to provide one for
those systems without it. However:
- X/Open defines `int isnan(double)`. Note the `int`.
- C99 defines `isnan(x)` to be a macro.
- C++11 nukes them all, undefines all the "masking macro"s, and
defines its own `bool isnan(double)`. Note the `bool`.
- In C++, `int isnan(double)` and `bool isnan(double)` are
incompatible.
- So the mess.
[Bug #14816][ruby-core:87364]
further reading: https://developers.redhat.com/blog/2016/02/29/why-cstdlib-is-more-complicated-than-you-might-think/
include/ruby/missing.h: defined(__cplusplus) before using __cplusplus
* include/ruby/missing.h (isinf, isnan): For non-C++ programs,
defined(__cplusplus) may be needed before using __cplusplus.
[Bug #14816]
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_2_4@64126 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
Diffstat (limited to 'include')
| -rw-r--r-- | include/ruby/missing.h | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/include/ruby/missing.h b/include/ruby/missing.h index 3474ca256f..7dbd29ffd1 100644 --- a/include/ruby/missing.h +++ b/include/ruby/missing.h @@ -162,6 +162,8 @@ RUBY_EXTERN const union bytesequence4_or_float rb_nan; # include <ieeefp.h> # endif # define isinf(x) (!finite(x) && !isnan(x)) +# elif defined(__cplusplus) && __cplusplus >= 201103L +# include <cmath> // it must include constexpr bool isinf(double); # else RUBY_EXTERN int isinf(double); # endif @@ -170,7 +172,11 @@ RUBY_EXTERN int isinf(double); #ifndef isnan # ifndef HAVE_ISNAN +# if defined(__cplusplus) && __cplusplus >= 201103L +# include <cmath> // it must include constexpr bool isnan(double); +# else RUBY_EXTERN int isnan(double); +# endif # endif #endif |