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| author | Jason Merrill <jason@redhat.com> | 2019-03-27 10:27:00 -0400 |
|---|---|---|
| committer | Jason Merrill <jason@gcc.gnu.org> | 2019-03-27 10:27:00 -0400 |
| commit | ce4609958f8db5cd64ec1c3bec624a36d8b35812 (patch) | |
| tree | 5fb7fdcf62bba0224c98e9af4d7bdbac59ac3b1e /gcc | |
| parent | 079c81dabf6a5f2fdb054651ec78f74a590a4ad0 (diff) | |
| download | gcc-ce4609958f8db5cd64ec1c3bec624a36d8b35812.zip gcc-ce4609958f8db5cd64ec1c3bec624a36d8b35812.tar.gz gcc-ce4609958f8db5cd64ec1c3bec624a36d8b35812.tar.bz2 | |
PR c++/86932 - missed SFINAE with empty pack.
The issue here was that when processing the explicit template args in
fn_type_unification we added an empty argument pack for the parameter pack,
so we never tried to do any deduction for it, and therefore never looked at
its type. We need that empty pack behavior for partial ordering, but we
don't want it here, so let's make it conditional on tf_partial.
* pt.c (coerce_template_parms): Don't add an empty pack if
tf_partial.
(fn_type_unification): Pass tf_partial to coerce_template_parms.
From-SVN: r269965
Diffstat (limited to 'gcc')
| -rw-r--r-- | gcc/cp/ChangeLog | 5 | ||||
| -rw-r--r-- | gcc/cp/pt.c | 3 | ||||
| -rw-r--r-- | gcc/testsuite/g++.dg/cpp0x/sfinae65.C | 15 |
3 files changed, 22 insertions, 1 deletions
diff --git a/gcc/cp/ChangeLog b/gcc/cp/ChangeLog index 550b754..bce9b10 100644 --- a/gcc/cp/ChangeLog +++ b/gcc/cp/ChangeLog @@ -1,5 +1,10 @@ 2019-03-26 Jason Merrill <jason@redhat.com> + PR c++/86932 - missed SFINAE with empty pack. + * pt.c (coerce_template_parms): Don't add an empty pack if + tf_partial. + (fn_type_unification): Pass tf_partial to coerce_template_parms. + PR c++/86429 - constexpr variable in lambda. PR c++/82643 PR c++/87327 diff --git a/gcc/cp/pt.c b/gcc/cp/pt.c index 05d5371..dc982f3 100644 --- a/gcc/cp/pt.c +++ b/gcc/cp/pt.c @@ -8436,6 +8436,7 @@ coerce_template_parms (tree parms, arg = NULL_TREE; if (template_parameter_pack_p (TREE_VALUE (parm)) + && (arg || !(complain & tf_partial)) && !(arg && ARGUMENT_PACK_P (arg))) { /* Some arguments will be placed in the @@ -20077,7 +20078,7 @@ fn_type_unification (tree fn, substitution context. */ explicit_targs = (coerce_template_parms (tparms, explicit_targs, NULL_TREE, - complain, + complain|tf_partial, /*require_all_args=*/false, /*use_default_args=*/false)); if (explicit_targs == error_mark_node) diff --git a/gcc/testsuite/g++.dg/cpp0x/sfinae65.C b/gcc/testsuite/g++.dg/cpp0x/sfinae65.C new file mode 100644 index 0000000..66790df --- /dev/null +++ b/gcc/testsuite/g++.dg/cpp0x/sfinae65.C @@ -0,0 +1,15 @@ +// PR c++/86932 +// { dg-do compile { target c++11 } } + +template<bool, typename T> struct enable_if { using type = T; }; +template<typename T> struct enable_if<false, T> { }; + +template<typename> struct is_foo { static constexpr bool value = false; }; + +// { dg-error "enable_if" "" { target *-*-* } .+1 } +template<class U, typename enable_if<is_foo<U>::value, int>::type...> void f() {} + +int main() +{ + f<int>(); // { dg-error "no match" } +} |