[The following information reflects version 4.6 of the C++ front end, which was released in March 2013.]

The front end accepts the C++ language as defined by the ISO/IEC 14882:2003 standard. It also accepts the C language as defined by the ISO/IEC 9899:1990 ("C89") and ISO/IEC 9899:1999 ("C99") standards and the "Embedded C" extensions of ISO/IEC TR 18037.

It also accepts almost all of the features in the recent ISO/IEC 14882:2011 ("C++11") standard:

  • static_assert
  • auto type in a declaration
  • rvalue references
  • alias templates
  • variadic templates
  • decltype
  • scoped enums
  • defaulted and deleted functions
  • nullptr
  • trailing return types on functions, and use of this therein
  • lambda expressions
  • new-style SFINAE for template deduction
  • standard attributes, e.g., [[noreturn]]
  • explicit conversion functions
  • char16_t and char32_t data types, and U-form Unicode literals
  • additional type traits, e.g., __underlying_type
  • initializer lists
  • namespace association, or "inline namespace"
  • the noexcept specifier and operator
  • range-based for loops
  • opaque enumeration definitions
  • generation of implicit move constructors and move assignment operators
  • constexpr
  • Nonstatic data member initializers (NSDMIs)
  • unrestricted unions
  • delegating constructors
  • raw and UTF-8 string literals
  • ref-qualifiers that apply to this in member functions

...and the rest will be coming soon. A complete list of C++11 features and the EDG releases in which they've been implemented can be retrieved by clicking here.

Accepting standard C++ and C is nice, but in the real world hardly any programs are written in completely standard-conforming C++ or C. The front end's "strict" standard C++ and C modes are useful for running test suites and ensuring that a program contains no nonstandard usage, but may be a bit too pedantic for everyday use. Therefore, the front end also offers slightly more relaxed default modes for C++ and C, and compatibility modes for some of the most popular compilers' dialects:

  • A Microsoft C and C++ compatibility mode, which provides the extensions supported by the Microsoft Visual C++ compiler (through version 11.0, including the C++/CLI features), along with various undocumented features and bugs.

  • A GNU C and C++ compatibility mode, which provides the extensions supported by GCC (versions 3.2-4.7), along with various undocumented features and bugs. The compatibility is good enough that the front end can compile the Linux kernel and utilities.

  • A Sun C++ compatibility mode.

  • A cfront compatibility mode, which emulates the old AT&T cfront processor.