On Mon, 12 Jun 2023, Ken Matsui via Libstdc++ wrote: > This patch implements built-in trait for std::is_reference. > > gcc/cp/ChangeLog: > > * cp-trait.def: 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.
LGTM > > Signed-off-by: Ken Matsui <kmat...@cs.washington.edu> > --- > gcc/cp/constraint.cc | 3 +++ > gcc/cp/cp-trait.def | 1 + > gcc/cp/semantics.cc | 4 +++ > gcc/testsuite/g++.dg/ext/has-builtin-1.C | 3 +++ > gcc/testsuite/g++.dg/ext/is_reference.C | 34 ++++++++++++++++++++++++ > 5 files changed, 45 insertions(+) > create mode 100644 gcc/testsuite/g++.dg/ext/is_reference.C > > diff --git a/gcc/cp/constraint.cc b/gcc/cp/constraint.cc > index 8cf0f2d0974..f6951ee2670 100644 > --- a/gcc/cp/constraint.cc > +++ b/gcc/cp/constraint.cc > @@ -3705,6 +3705,9 @@ 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 8b7fece0cc8..1e3310cd682 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 a2e74a5d2c7..2f37bc353a1 100644 > --- a/gcc/cp/semantics.cc > +++ b/gcc/cp/semantics.cc > @@ -12075,6 +12075,9 @@ 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); > > @@ -12289,6 +12292,7 @@ finish_trait_expr (location_t loc, cp_trait_kind > kind, tree type1, tree type2) > case CPTK_IS_ENUM: > case CPTK_IS_UNION: > case CPTK_IS_SAME: > + case CPTK_IS_REFERENCE: > break; > > case CPTK_IS_LAYOUT_COMPATIBLE: > 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..b5ce4db7afd > --- /dev/null > +++ b/gcc/testsuite/g++.dg/ext/is_reference.C > @@ -0,0 +1,34 @@ > +// { dg-do compile { target c++11 } } > + > +#include <testsuite_tr1.h> > + > +using namespace __gnu_test; > + > +#define SA(X) static_assert((X),#X) > +#define SA_TEST_CATEGORY(TRAIT, TYPE, EXPECT) \ > + SA(TRAIT(TYPE) == EXPECT); \ > + SA(TRAIT(const TYPE) == EXPECT); \ > + SA(TRAIT(volatile TYPE) == EXPECT); \ > + SA(TRAIT(const volatile TYPE) == EXPECT) > + > +// Positive tests. > +SA_TEST_CATEGORY(__is_reference, int&, true); > +SA_TEST_CATEGORY(__is_reference, ClassType&, true); > +SA(__is_reference(int(&)(int))); > +SA_TEST_CATEGORY(__is_reference, int&&, true); > +SA_TEST_CATEGORY(__is_reference, ClassType&&, true); > +SA(__is_reference(int(&&)(int))); > +SA_TEST_CATEGORY(__is_reference, IncompleteClass&, true); > + > +// Negative tests > +SA_TEST_CATEGORY(__is_reference, void, false); > +SA_TEST_CATEGORY(__is_reference, int*, false); > +SA_TEST_CATEGORY(__is_reference, int[3], false); > +SA(!__is_reference(int(int))); > +SA(!__is_reference(int(*const)(int))); > +SA(!__is_reference(int(*volatile)(int))); > +SA(!__is_reference(int(*const volatile)(int))); > + > +// Sanity check. > +SA_TEST_CATEGORY(__is_reference, ClassType, false); > +SA_TEST_CATEGORY(__is_reference, IncompleteClass, false); > -- > 2.41.0 > >