Extensions for C++11 compatibility

Note: IBM supports selected features of C++11, known as C++0x before its ratification. IBM will continue to develop and implement the features of this standard. The implementation of the language level is based on IBM's interpretation of the standard. Until IBM's implementation of all the C++11 features is complete, including the support of a new C++11 standard library, the implementation may change from release to release. IBM makes no attempt to maintain compatibility, in source, binary, or listings and other compiler interfaces, with earlier releases of IBM's implementation of the new C++11 features.

The following features are part of a continual phased release process leading towards full compliance with C++11. They can be enabled by using the -qlanglvl=extended0x group option. You can also use specific compiler options to enable or disable these features. See the following table.

Table 1. IBM XL C++ language extensions for compatibility with C++11
Language feature	Discussed in:	C++11 individual suboption control
Auto type deduction	The auto type specifier (C++11)	-qlanglvl=[no]autotypededuction
C99 `long long`	Types of integer literals in C99 and C++11	-qlanglvl=[no]c99longlong -qlanglvl=[no]extendedintegersafe
C99 preprocessor features adopted in C++11	C99 preprocessor features adopted in C++11 (C++11)	-qlanglvl=[no]c99preprocessor
Decltype	The decltype(expression) type specifier (C++11)	-qlanglvl=[no]decltype
Defaulted and deleted functions	Explicitly defaulted functions (C++11) Deleted functions (C++11)	-qlanglvl=[no]defaultanddelete
Delegating constructors	Delegating constructors (C++11)	-qlanglvl=[no]delegatingctors
Explicit conversion operators	Explicit conversion operators (C++11)	-qlanglvl=[no]explicitconversionoperators
Explicit instantiation declarations	Explicit instantiation declaration	-qlanglvl=[no]externtemplate
Extended friend declarations	Friends (C++ only)	-qlanglvl=[no]extendedfriend
Generalized constant expression	Generalized constant expressions (C++11)	-qlanglvl=[no]constexpr
Inline namespace definitions	Inline namespace definitions (C++11)	-qlanglvl=[no]inlinenamespace
Nullptr	Null pointers	-qlanglvl=[no]nullptr
Reference collapsing	Reference collapsing (C++11)	-qlanglvl=[no]referencecollapsing
Right angle brackets	Class templates (C++ only)	-qlanglvl=[no]rightanglebracket
Rvalue references	Using rvalue references (C++11)	-qlanglvl=[no]rvaluereferences
Scoped enumerations	Enumerations	-qlanglvl=[no]scopedenum
static_assert	static_assert declaration (C++11)	-qlanglvl=[no]static_assert
Trailing return type	Trailing return type (C++11)	-qlanglvl=[no]autotypededuction
Variadic templates	Variadic templates (C++11)	-qlanglvl=[no]variadic[templates]

Notes:

You can also use the -qlanglvl=extended group option to enable the explicit instantiation declarations feature.
If you try to use a C++11 feature when the feature is not enabled, the compiler issues an information message that follows a syntax error message. The information message indicates how to turn on the C++11 feature to recover from the syntax error. The involved C++11 features are listed as follows:
- C99 preprocessor features adopted in C++11
  - Mixed string literal concatenation
  - The __STDC_HOSTED__ macro
- Defaulted and deleted functions
- Delegating constructors
- Explicit conversion operators
- Generalized constant expressions
- Inline namespace definitions
- nullptr
- Reference collapsing
- Right angle brackets
- Rvalue references
- Scoped enumerations
- Variadic templates