why >?= and <?= don't work in VC++?
but they work fine in gcc/g++
like: a>?=b;
are they right usages?
Asked
Active
Viewed 263 times
3
lavinio
- 23,931
- 5
- 55
- 71
-
3What does it do in gcc? Never saw this before. – Jim Buck Aug 05 '09 at 15:53
-
If these are deprecated as bdonlan says, I would expect g++ to print a warning when you use them. I recommend compiling with "-Wall" (warn all, i.e. show all warnings) and trying to write code that produces no warnings. Can someone confirm that g++ does print a warning when you use these operators? – Tyler Aug 05 '09 at 17:18
-
a>?=b <==> a=MIN(a,b) I use vim with g++ and compile with "-Wall", but I never see a warning. – Aug 06 '09 at 13:49
2 Answers
13
Those operators are non-standard and are deprecated in GCC. They are not even supported in G++ at all anymore. You should use std::min and std::max instead. Be sure to #define NOMINMAX to disable the window-specific macros that conflict with them.
bdonlan
- 224,562
- 31
- 268
- 324
7
Because those are the old GC++-specific extensions for minimum and maximum.
From 6. Extensions to the C++ Language:
The GNU compiler provides these extensions to the C++ language (and you can also use most of the C language extensions in your C++ programs). If you want to write code that checks whether these features are available, you can test for the GNU compiler the same way as for C programs: check for a predefined macro
__GNUC__. You can also use__GNUG__to test specifically for GNU C++ (see section 'Predefined Macros' in The GNU C Preprocessor).
- 6.1 Minimum and Maximum Operators in C++ C++ Minimum and maximum operators.
- ...
Instead, you should use std::min and std::max.
lavinio
- 23,931
- 5
- 55
- 71