CODEWITHSUNDEEP
c++c++11
xis
xis

Reputation: 24850

C++11 predefined macro

Are there any predefined macros for C++ in order the code could identify the standard?

e.g. Currently most compilers puts "array" into "tr1" folder but for C++11 it would be part of STL. So currently

#include <tr1/array>

but c++11

#include <array>

What is the predefined macros for 03 standard and 11 standard in order I can use #ifdef to identify?

Also, I suppose there are macros for C90 and C99?

Thanksx

Upvotes: 24

Views: 15741

Answers (4)

Nicol Bolas
Nicol Bolas

Reputation: 473926

Ultimately, you're going to have to use compiler-specific information. At least, until C++0x becomes more widespreadly implemented. You basically need to pick driver versions that implement something and test compiler-specific macros on them.

The Boost.Config library has a number of macros that can help you.

Upvotes: 1

jcoder
jcoder

Reputation: 30035

From Stroustrup's C++11 FAQ

In C++11 the macro __cplusplus will be set to a value that differs from (is greater than) the current 199711L.

You can likely test it's value to determine if it's c++0x or not then.

Upvotes: 20

Sebastian Mach
Sebastian Mach

Reputation: 39099

From the draft N3242:

16.8 Predefined macro names                          [cpp.predefined]
...
   The name _ _ cplusplus is defined to the value 201103L when
   compiling a C++ translation unit. 155)
...
155) It is intended that future versions of this standard will
     replace the value of this macro with a greater value.
     Non-conforming compilers should use a value with at most five 
     decimal digits.

Upvotes: 7

Matthieu M.
Matthieu M.

Reputation: 299979

Nitpick...

Your particular issue does not depend on your compiler, it depends on the Standard Library implementation.

Since you are free to pick a different Standard Library that the one provided by your compiler (for example, trying out libc++ or stlport), no amount of compiler specific information will help you here.

Your best bet is therefore to create a specific header file yourself, in which you will choose either one or the other (depending on a build option).

// array.hpp
#ifdef STD_HAS_TR1_ARRAY_HEADER
#include <tr1/array>
#else
#include <array>
#endif

You then document the compiler option:

Passing -DSTD_HAS_TR1_ARRAY_HEADER will mean that std::tr1::array is defined in <tr1/array> instead of the default <array>.

And you're done.

Upvotes: 7

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