https://gcc.gnu.org/g:6586b015f1211ccd6e3e89b44dcb2116347edf89
commit r15-2650-g6586b015f1211ccd6e3e89b44dcb2116347edf89
Author: Jonathan Wakely <jwak...@redhat.com>
Date: Wed Mar 27 11:07:17 2024 +0000
libstdc++: Remove noexcept from non-const std::basic_string::data()
[PR99942]
The C++17 non-const overload of data() allows modifying the string
contents directly, so for the COW string we must do a copy-on-write to
unshare it. That means allocating, which can throw, so it shouldn't be
noexcept.
libstdc++-v3/ChangeLog:
PR libstdc++/99942
* include/bits/cow_string.h (data()): Change to noexcept(false).
Diff:
---
libstdc++-v3/include/bits/cow_string.h | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)
diff --git a/libstdc++-v3/include/bits/cow_string.h
b/libstdc++-v3/include/bits/cow_string.h
index 5d81bfc1230e..75a2d887ad63 100644
--- a/libstdc++-v3/include/bits/cow_string.h
+++ b/libstdc++-v3/include/bits/cow_string.h
@@ -2267,9 +2267,14 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
*
* This is a pointer to the character sequence held by the string.
* Modifying the characters in the sequence is allowed.
+ *
+ * The standard requires this function to be `noexcept` but for the
+ * Copy-On-Write string implementation it can throw. This function
+ * allows modifying the string contents directly, which means we
+ * must copy-on-write to unshare it, which requires allocating memory.
*/
_CharT*
- data() noexcept
+ data() noexcept(false)
{
_M_leak();
return _M_data();
