This patch implements built-in trait for std::is_reference. gcc/cp/ChangeLog:
* cp-trait.def (names_builtin_p): Define __is_reference. * constraint.cc (diagnose_trait_expr): Handle CPTK_IS_REFERENCE. * semantics.cc (trait_expr_value): Likewise. (finish_trait_expr): Likewise. gcc/testsuite/ChangeLog: * g++.dg/ext/has-builtin-1.C: Test existence of __is_reference. * g++.dg/ext/is_reference.C: New test. --- diff --git a/gcc/cp/constraint.cc b/gcc/cp/constraint.cc index 273d15ab097..23e5bc24dbb 100644 --- a/gcc/cp/constraint.cc +++ b/gcc/cp/constraint.cc @@ -3701,6 +3701,9 @@ diagnose_trait_expr (tree expr, tree args) case CPTK_HAS_VIRTUAL_DESTRUCTOR: inform (loc, " %qT does not have a virtual destructor", t1); break; + case CPTK_IS_REFERENCE: + inform (loc, " %qT is not a reference", t1); + break; case CPTK_IS_ABSTRACT: inform (loc, " %qT is not an abstract class", t1); break; diff --git a/gcc/cp/cp-trait.def b/gcc/cp/cp-trait.def index bac593c0094..63a64152ce6 100644 --- a/gcc/cp/cp-trait.def +++ b/gcc/cp/cp-trait.def @@ -67,6 +67,7 @@ DEFTRAIT_EXPR (IS_CONVERTIBLE, "__is_convertible", 2) DEFTRAIT_EXPR (IS_EMPTY, "__is_empty", 1) DEFTRAIT_EXPR (IS_ENUM, "__is_enum", 1) DEFTRAIT_EXPR (IS_FINAL, "__is_final", 1) +DEFTRAIT_EXPR (IS_REFERENCE, "__is_reference", 1) DEFTRAIT_EXPR (IS_LAYOUT_COMPATIBLE, "__is_layout_compatible", 2) DEFTRAIT_EXPR (IS_LITERAL_TYPE, "__is_literal_type", 1) DEFTRAIT_EXPR (IS_NOTHROW_ASSIGNABLE, "__is_nothrow_assignable", 2) diff --git a/gcc/cp/semantics.cc b/gcc/cp/semantics.cc index 87c2e8a7111..dce98af4f72 100644 --- a/gcc/cp/semantics.cc +++ b/gcc/cp/semantics.cc @@ -11995,6 +11995,9 @@ trait_expr_value (cp_trait_kind kind, tree type1, tree type2) case CPTK_IS_FINAL: return CLASS_TYPE_P (type1) && CLASSTYPE_FINAL (type1); + case CPTK_IS_REFERENCE: + return type_code1 == REFERENCE_TYPE; + case CPTK_IS_LAYOUT_COMPATIBLE: return layout_compatible_type_p (type1, type2); @@ -12139,6 +12142,7 @@ finish_trait_expr (location_t loc, cp_trait_kind kind, tree type1, tree type2) case CPTK_HAS_TRIVIAL_COPY: case CPTK_HAS_TRIVIAL_DESTRUCTOR: case CPTK_HAS_UNIQUE_OBJ_REPRESENTATIONS: + case CPTK_IS_REFERENCE: if (!check_trait_type (type1)) return error_mark_node; break; diff --git a/gcc/testsuite/g++.dg/ext/has-builtin-1.C b/gcc/testsuite/g++.dg/ext/has-builtin-1.C index f343e153e56..b697673790c 100644 --- a/gcc/testsuite/g++.dg/ext/has-builtin-1.C +++ b/gcc/testsuite/g++.dg/ext/has-builtin-1.C @@ -146,3 +146,6 @@ #if !__has_builtin (__remove_cvref) # error "__has_builtin (__remove_cvref) failed" #endif +#if !__has_builtin (__is_reference) +# error "__has_builtin (__is_reference) failed" +#endif diff --git a/gcc/testsuite/g++.dg/ext/is_reference.C b/gcc/testsuite/g++.dg/ext/is_reference.C new file mode 100644 index 00000000000..b4f048538e5 --- /dev/null +++ b/gcc/testsuite/g++.dg/ext/is_reference.C @@ -0,0 +1,26 @@ +// { dg-do compile { target c++11 } } + +#define SA(X) static_assert((X),#X) + +SA(!__is_reference(void)); +SA(!__is_reference(int*)); + +SA(__is_reference(int&)); +SA(__is_reference(const int&)); +SA(__is_reference(volatile int&)); +SA(__is_reference(const volatile int&)); + +SA(__is_reference(int&&)); +SA(__is_reference(const int&&)); +SA(__is_reference(volatile int&&)); +SA(__is_reference(const volatile int&&)); + +SA(!__is_reference(int[3])); +SA(!__is_reference(const int[3])); +SA(!__is_reference(volatile int[3])); +SA(!__is_reference(const volatile int[3])); + +SA(!__is_reference(int(int))); +SA(!__is_reference(int(*const)(int))); +SA(!__is_reference(int(*volatile)(int))); +SA(!__is_reference(int(*const volatile)(int)));