C++ Support in Clang

This page tracks the status of C++ support in Clang.
Currently most of the C++ features are missing; here you can find features that are at least partially supported in Clang. If you are looking to get involved with Clang development to help work on support for C++, please also look at our Open Projects page for some specific ideas.

The following table is used to help track our implementation progress toward implementing the complete C++03 standard. We use a simple, somewhat arbitrary color-coding scheme to describe the relative completeness of features by section:

Not started/not evaluated	Not Applicable	Broken	Some examples work	Many examples work	Nearly everything works	Complete	Complete (with tests for each paragraph)
	N/A						✓

A feature is "complete" when the appropriate Clang component (Parse, AST, Sema, CodeGen) implements the behavior described in all of the paragraphs in the relevant C++ standard. Note that many C++ features are actually described in several different sections within the standard. The major components are:

Parse: Clang is able to parse the grammar of this feature (or the grammar described by this section), but does not necessarily do anything with the parsed result. Use Clang's -fsyntax-only option to parse C++ programs.
AST: Clang builds an abstract syntax tree (AST) for the feature, but does not necessarily perform any type-checking. Use Clang's -ast-print option to print the resulting ASTs.
Sema: Clang parses and type-checks this feature and provides a well-formed AST annotated with types. Use Clang's -fsyntax-only to type-check code.
CodeGen: Clang parses, type-checks, and generates code for this feature, allowing one to compile and execute programs.

Updates to this table are welcome! Since Clang already supports much of C, and therefore much C++, many of the currently-white cells could be filled in. If you wish to do so, please compare Clang's implementation against the C++ standard and provide a patch that updates the table accordingly. Tests for the various features are also welcome!

Section	Parse	AST	Sema	CodeGen	Notes
2 [lex]		N/A	N/A	N/A
2.1 [lex.phases]		N/A	N/A	N/A	Extended characters aren't handled.
2.2 [lex.charset]		N/A	N/A	N/A	No support for extended characters.
2.3 [lex.trigraph]		N/A	N/A	N/A
2.4 [lex.pptoken]		N/A	N/A	N/A
2.5 [lex.digraph]		N/A	N/A	N/A
2.6 [lex.token]		N/A	N/A	N/A
2.7 [lex.comment]			N/A	N/A	NDR "form feed or vtab in comment" is not diagnosed. No AST representation of comments.
2.8 [lex.header]		N/A	N/A	N/A
2.9 [lex.ppnumber]		N/A	N/A	N/A
2.10 [lex.name]		N/A	N/A	N/A	No support for extended characters
2.11 [lex.key]		N/A	N/A	N/A
2.12 [lex.operators]		N/A	N/A	N/A
2.13 [lex.literal]		N/A	N/A	N/A
2.13.1 [lex.icon]		N/A	N/A	N/A
2.13.2 [lex.ccon]		N/A	N/A	N/A	Poor support for extended characters
2.13.3 [lex.fcon]		N/A	N/A	N/A
2.13.4 [lex.string]		N/A	N/A	N/A	Poor support for extended characters
2.13.5 [lex.bool]		N/A	N/A	N/A
3 [basic]	N/A	N/A	N/A	N/A
3.1 [basic.def]				N/A
3.2 [basic.def.odr]
3.3 [basic.scope]	N/A	N/A		N/A
3.3.1 [basic.scope.pdecl]	N/A	N/A		N/A
3.3.2 [basic.scope.local]	N/A	N/A		N/A
3.3.3 [basic.scope.proto]	N/A	N/A		N/A
3.3.4 [basic.funscope]	N/A	N/A		N/A
3.3.5 [basic.scope.namespace]
3.3.6 [basic.scope.class]
3.3.7 [basic.scope.hiding]	N/A	N/A		N/A
3.4 [basic.lookup]	N/A	N/A		N/A
3.4.1 [basic.lookup.unqual]	N/A	N/A		N/A	Many cases beyond simple global and function-local lookup don't work
3.4.2 [basic.lookup.argdep]	N/A			N/A	Missing support for templates, friend functions.
3.4.3 [basic.lookup.qual]	N/A	N/A		N/A
3.4.3.1 [class.qual]	N/A	N/A		N/A
3.4.3.2 [namespace.qual]	N/A	N/A		N/A
3.4.4 [basic.lookup.elab]
3.4.5 [basic.lookup.classref]
3.4.6 [basic.lookup.udir]
3.5 [basic.link]
3.6 [basic.start]
3.6.1 [basic.start.main]
3.6.2 [basic.start.init]
3.6.3 [basic.start.term]
3.7 [basic.stc]
3.7.1 [basic.stc.static]
3.7.2 [basic.stc.auto]
3.7.3 [basic.stc.dynamic]
3.7.3.1 [basic.stc.dynamic.allocation]
3.7.3.2 [basic.stc.dynamic.deallocation]
3.7.4 [basic.stc.inherit]
3.8 [basic.life]
3.9 [basic.types]
3.9.1 [basic.fundamental]
3.9.2 [basic.compound]
3.9.3 [basic.type.qualifier]
3.10 [basic.lval]
4 [conv]
4.1 [conv.lval]
4.2 [conv.array]
4.3 [conv.func]
4.4 [conv.qual]
4.5 [conv.prom]
4.6 [conv.fpprom]
4.7 [conv.integral]
4.8 [conv.double]
4.9 [conv.fpint]
4.10 [conv.ptr]
4.11 [conv.mem]
4.12 [conv.bool]
5 [expr]	N/A	N/A
5.1 [expr.prim]					template-ids are not supported, name lookup is not complete
5.2 [expr.post]
5.2.1 [expr.sub]
5.2.2 [expr.call]
5.2.3 [expr.type.conv]					Only between non-class types
5.2.4 [expr.pseudo]
5.2.5 [expr.ref]					Cannot look up operator names, qualified-ids, or names in base classes
5.2.6 [expr.post.incr]
5.2.7 [expr.dynamic.cast]
5.2.8 [expr.typeid]
5.2.9 [expr.static.cast]					Some custom conversions don't work.
5.2.10 [expr.reinterpret.cast]
5.2.11 [expr.const.cast]
5.3 [expr.unary]
5.3.1 [expr.unary.op]
5.3.1p1 Unary *
5.3.1p2-5 Unary &
5.3.1p6 Unary +
5.3.1p7 Unary -
5.3.1p8 Unary !
5.3.1p9 Unary ~
5.3.2 [expr.pre.incr]
5.3.3 [expr.sizeof]
5.3.4 [expr.new]					operator delete is not looked up, initialization not quite correct
5.3.5 [expr.delete]
5.4 [expr.cast]					Too lenient, and may not always have correct semantics
5.5 [expr.mptr.oper]					Dereferenced member function pointers have the wrong type.
5.6 [expr.mul]
5.7 [expr.add]
5.8 [expr.shift]
5.9 [expr.rel]
5.10 [expr.eq]
5.11 [expr.bit.and]
5.12 [expr.xor]
5.13 [expr.or]
5.14 [expr.log.and]
5.15 [expr.log.or]
5.16 [expr.cond]					some invalid hierarchy casts still accepted, but that's a general problem
5.17 [expr.ass]
5.18 [expr.comma]
5.19 [expr.const]					Uses C semantics
6 [stmt.stmt]
6.1 [stmt.label]
6.2 [stmt.expr]
6.3 [stmt.block]
6.4 [stmt.select]					Conversion of declarations to required types not really supported.
6.4.1 [stmt.if]
6.4.2 [stmt.switch]
6.5 [stmt.iter]					Conversion of declarations to required types not really supported.
6.5.1 [stmt.while]
6.5.2 [stmt.do]
6.5.3 [stmt.for]
6.6 [stmt.jump]
6.6.1 [stmt.break]
6.6.2 [stmt.cont]
6.6.3 [stmt.return]
6.6.4 [stmt.goto]
6.7 [stmt.dcl]					Skipping of initialization is not flagged. Existence and accessibility of destructors is not tested for.
6.8 [stmt.ambig]
7 [dcl.dcl]
7.1 [dcl.spec]					No support for friend declarations.
7.1.1 [dcl.stc]					Linkage merging has some errors.
7.1.2 [dcl.fct.spec]
7.1.3 [dcl.typedef]
7.1.4 [dcl.friend]
7.1.5 [dcl.type]
7.1.5.1 [dcl.type.cv]
7.1.5.2 [dcl.type.simple]					Cannot parse template IDs.
7.1.5.3 [dcl.type.elab]					Cannot parse template IDs.
7.2 [dcl.enum]
7.3 [basic.namespace]
7.3.1 [namespace.def]					Cannot parse namespace aliases.
7.3.1.1 [namespace.unnamed]					Unnamed namespace members cannot be looked up.
7.3.1.2 [namespace.memdef]					The friend stuff is not supported.
7.3.2 [namespace.alias]				N/A
7.3.3 [namespace.udecl]
7.3.4[namespace.udir]					Example in p4 fails.
7.4 [dcl.asm]
7.5 [dcl.link]
8 [dcl.decl]
8.1 [dcl.name]				N/A
8.2 [dcl.ambig.res]	✓	N/A	✓	N/A
8.3 [dcl.meaning]				N/A	Qualified declarator-ids are not fully implemented.
8.3.1 [dcl.ptr]				N/A
8.3.2 [dcl.ref]				N/A
8.3.3 [dcl.mptr]				N/A
8.3.4 [dcl.array]				N/A
8.3.5 [dcl.fct]				N/A
8.3.6 [dcl.fct.default]				N/A	Missing default arguments for templates.
8.4 [dcl.fct.def]					ctor-initializers are not fully type-checked.
8.5 [dcl.init]
8.5.1[dcl.init.aggr]					No CodeGen for initializing non-aggregates or dynamic initialization.
8.5.2[dcl.init.string]
8.5.3 [dcl.init.ref]
9 [class]
9.1 [class.name]				N/A
9.2 [class.mem]					No parser support for using declarations or member templates.
9.3 [class.mfct]
9.3.1 [class.mfct.non-static]
9.3.2 [class.this]
9.4 [class.static]
9.4.1 [class.static.mfct]
9.4.2 [class.static.data]
9.5 [class.union]					Semantic analysis does not yet check all of the requirements placed on the members of unions.
9.6 [class.bit]
9.7 [class.nest]				N/A
9.8 [class.local]	✓	✓	✓	N/A
9.9 [class.nested.type]	✓	✓	✓	N/A
10 [class.derived]
10.1 [class.mi]					No layout of base classes
10.2 [class.member.lookup]				N/A
10.3 [class.virtual]					No semantic analysis for overriding virtual functions or inheriting a virtual function. No layout of classes with virtual functions.
10.4 [class.abstract]				N/A
11 [class.access]				N/A
11.1 [class.access.spec]				N/A
11.2 [class.access.base]				N/A
11.3 [class.access.dcl]				N/A
11.4 [class.friend]				N/A
11.5 [class.protected]				N/A
11.6 [class.access.virt]				N/A
11.7 [class.paths]				N/A
11.8 [class.access.nest]				N/A
12 [special]
12.1 [class.ctor]					Implicitly-declared constructors are never defined.
12.2 [class.temporary]	N/A				Implementation of temporary objects is in its initial stages.
12.3 [class.conv]
12.3.1 [class.conv.ctor]
12.3.2 [class.conv.fct]					No support for inheritance of conversion functions.
12.4 [class.dtor]					Most of the semantics of destructors are unimplemented.
12.5 [class.free]
12.6 [class.init]
12.6.1 [class.expl.init]
12.6.2 [class.base.init]					No actual direct initialization; implicit initialization not checked.
12.7 [class.cdtor]
12.8 [class.copy]					Copy assignment operators are mostly ignored by semantic analysis.
13 [over]
13.1 [over.load]					Missing name mangling.
13.2 [over.dcl]
13.3 [over.match]
13.3.1 [over.match.funcs]
13.3.1.1 [over.match.call]
13.3.1.1.1 [over.call.func]
13.3.1.1.2 [over.call.object]					Missing AST representation for the implicit conversion to a function reference/pointer
13.3.1.2 [over.match.oper]
13.3.1.3 [over.match.ctor]
13.3.1.4 [over.match.copy]
13.3.1.5 [over.match.conv]
13.3.1.6 [over.match.ref]
13.3.2 [over.match.viable]
13.3.3 [over.match.best]
13.3.3.1 [over.best.ics]
13.3.3.1.1 [over.ics.scs]
13.3.3.1.2 [over.ics.user]
13.3.3.1.3 [over.ics.ellipsis]
13.3.3.1.4 [over.ics.ref]
13.3.3.2 [over.ics.rank]
13.4 [over.over]					Error messages need some work. Without templates or using declarations, we don't have any ambiguities, so the semantic analysis is incomplete.
13.5 [over.oper]					Some overloaded operators can only be called with function syntax, e.g., `operator[](x)`.
13.5.1 [over.unary]	N/A
13.5.2 [over.binary]	N/A
13.5.3 [over.ass]	N/A
13.5.4 [over.call]	N/A
13.5.5 [over.sub]	N/A
13.5.6 [over.ref]	N/A
13.5.7 [over.inc]	N/A
13.6 [over.built]	N/A				Missing pointer-to-member versions (p11, p16) and support for the ternary operator (p24, p25).
14 [temp]	N/A
14.1 [temp.param]	✓	✓		N/A	Template template parameters cannot actually be used in templates
14.2 [temp.names]				N/A	Cannot name function template specializations
14.3 [temp.arg]				N/A	Cannot name function template specializations
14.3.1 [temp.arg.type]	✓	✓		N/A	Paragraph 3 will be tested elsewhere
14.3.2 [temp.arg.nontype]				N/A
14.3.3 [temp.arg.template]				N/A
14.4 [temp.type]	N/A	✓	✓	N/A
14.5 [temp.decls]
14.5.1 [temp.class]					No out-of-line definitions of the members of a template.
14.5.1.1 [temp.mem.func]					No out-of-line definitions of the member functions of a class template.
14.5.1.2 [temp.mem.class]					No out-of-line definitions of the member classes of a class template.
14.5.1.3 [temp.static]					No out-of-line definitions of the static data members of a class template.
14.5.2 [temp.mem]
14.5.3 [temp.friend]				N/A
14.5.4 [temp.class.spec]				N/A
14.5.4.1 [temp.class.spec.match]	N/A	N/A		N/A
14.5.4.2 [temp.class.order]				N/A
14.5.5.3 [temp.class.spec.mfunc]				N/A
14.5.5 [temp.fct]
14.5.5.1 [temp.over.link]				N/A
14.5.5.2 [temp.func.order]				N/A
14.6 [temp.res]
14.6.1 [temp.local]
14.6.2 [temp.dep]	N/A
14.6.2.1 [temp.dep.type]	N/A
14.6.2.2 [temp.dep.expr]	N/A
14.6.2.3 [temp.dep.constexpr]	N/A
14.6.2.4 [temp.dep.temp]	N/A
14.6.3 [temp.nondep]	N/A
14.6.4 [temp.dep.res]	N/A
14.6.4.1 [temp.point]	N/A
14.6.4.2 [temp.dep.candidate]	N/A				Not restricted to functions with external linkage
14.6.5 [temp.inject]	N/A
14.7 [temp.spec]					Function templates cannot be instantiated
14.7.1 [temp.inst]	N/A				Function templates cannot be instantiated
14.7.2 [temp.explicit]					Function templates cannot be instantiated
14.7.3 [temp.expl.spec]					Only class template specialization is available
14.8 [temp.fct.spec]
14.8.1 [temp.arg.explicit]
14.8.2 [temp.deduct]	N/A	N/A		N/A
14.8.2.1 [temp.deduct.call]
14.8.2.2 [temp.deduct.funcaddr]
14.8.2.3 [temp.deduct.conv]
14.8.2.4 [temp.deduct.type]	N/A			N/A
14.8.3 [temp.over]
15 [except]
15.1 [except.throw]	N/A	N/A			Does not check for existence of copy constructor and destructor, and some other details
15.2 [except.ctor]	N/A	N/A	N/A
15.3 [except.handle]	N/A	N/A			Not all constraints are checked
15.4 [except.spec]
15.5 [except.special]	N/A	N/A	N/A	N/A
15.5.1 [except.terminate]	N/A	N/A	N/A	N/A
15.5.2 [except.unexpected]	N/A	N/A	N/A	N/A
15.5.3 [except.uncaught]	N/A	N/A	N/A	N/A
15.6 [except.access]	N/A	N/A	N/A	N/A	Redundant - struck from C++0x
16 [cpp]
16.1 [cpp.cond]
16.2 [cpp.include]
16.3 [cpp.replace]
16.3.1 [cpp.subst]
16.3.2 [cpp.stringize]
16.3.3 [cpp.concat]
16.3.4 [cpp.rescan]
16.3.5 [cpp.scope]
16.4 [cpp.line]
16.5 [cpp.error]
16.6 [cpp.pragma]
16.7 [cpp.null]
16.8 [cpp.predefined]
A [gram]
A.1 [gram.key]
A.2 [gram.lex]
A.3 [gram.basic]
A.4 [gram.expr]
A.5 [gram.stmt]
A.6 [gram.dcl]
A.7 [gram.decl]
A.8 [gram.class]
A.9 [gram.derived]
A.10 [gram.special]
A.11 [gram.over]
A.12 [gram.temp]
A.13 [gram.except]
A.14 [gram.cpp]
B [implimits]
C [diff]
C.1 [diff.iso]
C.1.1 [diff.lex]
C.1.2 [diff.basic]
C.1.3 [diff.expr]
C.1.4 [diff.stat]
C.1.5 [diff.dcl]
C.1.6 [diff.decl]
C.1.7 [diff.class]
C.1.8 [diff.special]
C.1.9 [diff.cpp]
C.2 [diff.library]
C.2.1 [diff.mods.to.headers]
C.2.2 [diff.mods.to.definitions]
C.2.2.2 [diff.wchar.t]
C.2.2.3 [diff.header.iso646.h]
C.2.2.4 [diff.null]
C.2.3 [diff.mods.to.declarations]
C.2.4 [diff.mods.to.behavior]
C.2.4.1 [diff.offsetof]
C.2.4.2 [diff.malloc]
D [depr]
D.1 [depr.incr.bool]
D.2 [depr.static]
D.3 [depr.access.dcl]
D.4 [depr.string]
D.5 [depr.c.headers]
E [extendid]
C++0x Features
Explicit conversion operators (N2437)					No name mangling; ASTs don't contain calls to conversion operators
Static assertions (N1720)				N/A
Deleted functions (N2346)				N/A
Rvalue references (N2118 + N2831)
nullptr (N2431)
Right angle brackets (N1757)		N/A	N/A	N/A
Decltype (N2343)	✓	✓	✓	N/A