C++11/14 compiler and library shootout

It’s been almost a year since my last comparison of C++11 support across different compilers, so I decided to take a break from working on my book about C++11/14 features in VS2013, and see how things have changed.

Once again, I’d like to see how different compilers stack up based on the documentation for the pre-release versions of these compilers. I’ve also included some of the current released versions for comparison.

Of course, now we have C++14 to think about in addition to C++11, so I’ve included C++14 in this comparison too.

The pre-release versions of the compilers are as follows: GCC 4.9, Clang 3.4 and Visual Studio Nov 2013 CTP.

First, let’s look at the C++11 language features. Clang 3.3 and above, and GCC 4.8 and later have complete support, so there was no point including them in the table.

C++11 language features support

Feature	VS Nov 2013 CTP	VS2013	Intel 14.0
auto	Yes	Yes	Yes
decltype	Yes	Yes	Yes
Lambda expressions	Yes	Yes	Yes
nullptr	Yes	Yes	Yes
static_assert	Yes	Yes	Yes
Range based for loop	Yes	Yes	Yes
Trailing return type in functions	Yes	Yes	Yes
extern templates	Yes	Yes	Yes
>> for nested templates	Yes	Yes	Yes
Local and unnamed types as template arguments	Yes	Yes	Yes
Variadic macros	Yes	Yes	Yes
Variadic templates	Yes	Yes	Yes
Default template arguments in function templates	Yes	Yes	Yes
final method keyword	Yes	Yes	Yes
override method keyword	Yes	Yes	Yes
Strongly typed enums	Yes	Yes	Yes
Forward declared enums	Yes	Yes	Yes
Explicit type conversion operators	Yes	Yes	Yes
Raw string literals	Yes	Yes	Yes
Delegating constructors	Yes	Yes	Yes
Template aliases	Yes	Yes	Yes
Non-static data member initializers	Yes	Yes	Yes
Deleted methods	Yes	Yes	Yes
Initializer lists	Yes	Partial	Yes
Rvalue references and move semantics	Yes	Partial	Yes
Defaulted methods	Yes	Partial	Yes
C99 compatibility	Partial	Partial	Yes
New built-in types	Partial	Partial	Partial
Member function ref qualifiers	Yes	No	Yes
noexcept	Partial	No	Yes
constexpr	Partial	No	Yes
Alignment support	Yes	Partial	No
Magic statics	Yes	No	Partial
Thread local storage	Partial	Partial	No
Generalized attributes	No	No	Yes
Inline namespaces	No	No	Yes
sizeof on non-static data members without an instance	Yes	No	No
Encoding support in literals	No	No	Yes
Arbitrary expressions in template deduction contexts	No	No	Yes
Inheriting constructors	Yes	No	No
Changed restrictions on union members	No	No	Partial
User defined literals	No	No	No

It looks like the Intel compiler is on par with the Visual Studio CTP. But Intel’s 14.0 compiler has been out for some time, while VS CTP is an alpha quality compiler, which means that Visual Studio trails behind everybody else, unfortunately.

How about C++14 support? The C++ standard is still in draft, but some compilers already have extensive support for C++14 language features:

C++14 language features support

Feature	Clang 3.4	GCC 4.9	VS Nov 2013 CTP	Intel 14.0
Return type deduction for regular functions	Yes	Yes	Yes	No
Binary literals	Yes	Yes	No	Yes
Generic lambdas	Yes	Yes	Partial	No
Tweaked wording for contextual conversions	Yes	Yes	No	No
Runtime sized arrays with automatic storage duration	Yes	Yes	No	No
Initialized lambda captures	Yes	Yes	No	No
[[deprecated]] attribute	Yes	Yes	No	No
Single quotation mark as digit separator	Yes	Yes	No	No
C++ sized deallocation	Yes	Yes	No	No
Variable templates	Yes	No	No	No
Relaxed requirements on constexpr functions	Yes	No	No	No
Member initializers and aggregates	Yes	No	No	No
Avoiding/fusing memory allocations	Yes	N/A	No	No

As far as libraries go, libstdc++, libc++ and Microsoft’s libraries all have at least partial support for all the features introduced in C++11. So instead of detailing those, I’ll focus on C++14 features. Once again, this is for the latest pre-release versions of the libraries available today:

C++14 library features support

Feature	libc++	libstdc++	VS Nov 2013 CTP
make_unique	Yes	Yes	Yes
Improved operator functors	Yes	Yes	Yes
Additional template aliases for transformation type traits	Yes	Yes	Yes
Fixing constexpr member functions without const	Yes	Yes	No
exchange() utility function	Yes	Yes	No
Retrieving tuple elements by type	Yes	Yes	No
std::result_of and SFINAE	Yes	Yes	No
Improvements to integral_constant	Yes	Yes	No
User-defined literals for standard library types	Yes	Yes	No
More robust non-modifying sequence operations	Yes	Yes	No
Quoted string I/O manipulator	Yes	Yes	No
constexpr library additions: chrono	Yes	Yes	No
constexpr library additions: containers	Yes	Yes	No
constexpr library additions: utilities	Yes	Yes	No
constexpr library additions: complex	Yes	No	No
constexpr library additions: functional	Yes	No	No
Compile-time integer sequences	Yes	Yes	No
Shared locking	Yes	Yes	No
Heterogeneous comparison lookup in associative containers	Yes	No	No
Null forward iterators	Yes	No	No
Sized deallocation	No	No	No
Consistent metafunction aliases	No	No	No
Discouraging rand() in C++14	No	No	No

Conclusion

Clang is obviously leading on the C++14 conformance front. There are also quite a few features implemented in GCC as well.

The interesting thing is that the process of building compilers to conform to the latest C++ standard has accelerated in recent years. With C++14, Clang has complete language support even before the standard has been finalized.

But it would be really great if Microsoft and Intel picked up their game, and brought their compilers’ conformance to the level of Clang and GCC.

Keen on mastering C++11/14? I've written books focused on C++11/14 features. You can get a VS2013, Clang or a GCC edition.