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| author | Patrick Palka <ppalka@redhat.com> | 2024-07-23 11:37:31 -0400 |
|---|---|---|
| committer | Patrick Palka <ppalka@redhat.com> | 2024-07-23 11:37:31 -0400 |
| commit | f70281222df432a7bec1271904c5ebefd7f2c934 (patch) | |
| tree | 6c7d7dca1344b52810384dbc51623840ac988aae | |
| parent | 7f8064ff0e2ac90c5bb6c30cc61acc5a28ebbe4c (diff) | |
| download | gcc-f70281222df432a7bec1271904c5ebefd7f2c934.zip gcc-f70281222df432a7bec1271904c5ebefd7f2c934.tar.gz gcc-f70281222df432a7bec1271904c5ebefd7f2c934.tar.bz2 | |
c++: missing SFINAE during alias CTAD [PR115296]
During the alias CTAD transformation, if substitution failed for some
guide we should just silently discard the guide. We currently do
discard the guide, but not silently, as in the below testcase which
we diagnose forming a too-large array type when transforming the
user-defined deduction guides.
This patch fixes this by using complain=tf_none instead of
tf_warning_or_error throughout alias_ctad_tweaks.
PR c++/115296
gcc/cp/ChangeLog:
* pt.cc (alias_ctad_tweaks): Use complain=tf_none instead of
tf_warning_or_error.
gcc/testsuite/ChangeLog:
* g++.dg/cpp2a/class-deduction-alias23.C: New test.
Reviewed-by: Jason Merrill <jason@redhat.com>
| -rw-r--r-- | gcc/cp/pt.cc | 2 | ||||
| -rw-r--r-- | gcc/testsuite/g++.dg/cpp2a/class-deduction-alias23.C | 19 |
2 files changed, 20 insertions, 1 deletions
diff --git a/gcc/cp/pt.cc b/gcc/cp/pt.cc index 108e929b..8cc5e21 100644 --- a/gcc/cp/pt.cc +++ b/gcc/cp/pt.cc @@ -30287,7 +30287,7 @@ alias_ctad_tweaks (tree tmpl, tree uguides) (INNERMOST_TEMPLATE_PARMS (fullatparms))); } - tsubst_flags_t complain = tf_warning_or_error; + tsubst_flags_t complain = tf_none; tree aguides = NULL_TREE; tree atparms = INNERMOST_TEMPLATE_PARMS (fullatparms); unsigned natparms = TREE_VEC_LENGTH (atparms); diff --git a/gcc/testsuite/g++.dg/cpp2a/class-deduction-alias23.C b/gcc/testsuite/g++.dg/cpp2a/class-deduction-alias23.C new file mode 100644 index 0000000..117212c --- /dev/null +++ b/gcc/testsuite/g++.dg/cpp2a/class-deduction-alias23.C @@ -0,0 +1,19 @@ +// PR c++/115296 +// { dg-do compile { target c++20 } } + +using size_t = decltype(sizeof(0)); + +template<class T, size_t N = size_t(-1)> +struct span { span(T); }; + +template<class T, size_t N> +span(T(&)[N]) -> span<T, N>; // { dg-bogus "array exceeds maximum" } + +template<class T, size_t N> +requires (sizeof(T[N]) != 42) // { dg-bogus "array exceeds maximum" } +span(T*) -> span<T, N>; + +template<class T> +using array_view = span<T>; + +array_view x = 0; |