diff options
Diffstat (limited to 'gcc/doc/invoke.texi')
| -rw-r--r-- | gcc/doc/invoke.texi | 22 |
1 files changed, 21 insertions, 1 deletions
diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi index 8be2b4f..665c0ff 100644 --- a/gcc/doc/invoke.texi +++ b/gcc/doc/invoke.texi @@ -236,7 +236,8 @@ in the following sections. -Wabi-tag -Wcatch-value -Wcatch-value=@var{n} @gol -Wno-class-conversion -Wclass-memaccess @gol -Wcomma-subscript -Wconditionally-supported @gol --Wno-conversion-null -Wctor-dtor-privacy -Wno-delete-incomplete @gol +-Wno-conversion-null -Wctad-maybe-unsupported @gol +-Wctor-dtor-privacy -Wno-delete-incomplete @gol -Wdelete-non-virtual-dtor -Wdeprecated-copy -Wdeprecated-copy-dtor @gol -Weffc++ -Wextra-semi -Wno-inaccessible-base @gol -Wno-inherited-variadic-ctor -Wno-init-list-lifetime @gol @@ -3304,6 +3305,25 @@ void f(int *a, int b, int c) @{ Enabled by default with @option{-std=c++20}. +@item -Wctad-maybe-unsupported @r{(C++ and Objective-C++ only)} +@opindex Wctad-maybe-unsupported +@opindex Wno-ctad-maybe-unsupported +Warn when performing class template argument deduction (CTAD) on a type with +no explicitly written deduction guides. This warning will point out cases +where CTAD succeeded only because the compiler synthesized the implicit +deduction guides, which might not be what the programmer intended. Certain +style guides allow CTAD only on types that specifically "opt-in"; i.e., on +types that are designed to support CTAD. This warning can be suppressed with +the following pattern: + +@smallexample +struct allow_ctad_t; // any name works +template <typename T> struct S @{ + S(T) @{ @} +@}; +S(allow_ctad_t) -> S<void>; // guide with incomplete parameter type will never be considered +@end smallexample + @item -Wctor-dtor-privacy @r{(C++ and Objective-C++ only)} @opindex Wctor-dtor-privacy @opindex Wno-ctor-dtor-privacy |