On 9/8/21 3:52 PM, Jonathan Wakely via Gcc-patches wrote:
Ping (and remember to CC a maintainer this time).
OK, thanks.
On 31/08/21 09:53 +0100, Jonathan Wakely wrote:
The description of behaviour is incorrect, the virtual base gets
assigned before entering the bodies of A::operator= and B::operator=,
not after.
The example is also ill-formed (passing a string literal to char*) and
undefined (missing return from Base::operator=).
Signed-off-by: Jonathan Wakely <jwak...@redhat.com>
gcc/ChangeLog:
PR c++/60318
* doc/trouble.texi (Copy Assignment): Fix description of
behaviour and fix code in example.
OK for trunk and all active branches?
commit f0fa91971e35c1df7381ac289ece9bd5f07f8535
Author: Jonathan Wakely <jwak...@redhat.com>
Date: Tue Aug 31 09:46:41 2021
c++: Fix docs on assignment of virtual bases [PR60318]
The description of behaviour is incorrect, the virtual base gets
assigned before entering the bodies of A::operator= and B::operator=,
not after.
The example is also ill-formed (passing a string literal to char*) and
undefined (missing return from Base::operator=).
Signed-off-by: Jonathan Wakely <jwak...@redhat.com>
gcc/ChangeLog:
PR c++/60318
* doc/trouble.texi (Copy Assignment): Fix description of
behaviour and fix code in example.
diff --git a/gcc/doc/trouble.texi b/gcc/doc/trouble.texi
index 40c51ae21cb..8b34be4aa63 100644
--- a/gcc/doc/trouble.texi
+++ b/gcc/doc/trouble.texi
@@ -865,10 +865,11 @@ objects behave unspecified when being assigned.
For example:
@smallexample
struct Base@{
char *name;
- Base(char *n) : name(strdup(n))@{@}
+ Base(const char *n) : name(strdup(n))@{@}
Base& operator= (const Base& other)@{
free (name);
name = strdup (other.name);
+ return *this;
@}
@};
@@ -901,8 +902,8 @@ inside @samp{func} in the example).
G++ implements the ``intuitive'' algorithm for copy-assignment: assign
all
direct bases, then assign all members. In that algorithm, the virtual
base subobject can be encountered more than once. In the example,
copying
-proceeds in the following order: @samp{val}, @samp{name} (via
-@code{strdup}), @samp{bval}, and @samp{name} again.
+proceeds in the following order: @samp{name} (via @code{strdup}),
+@samp{val}, @samp{name} again, and @samp{bval}.
If application code relies on copy-assignment, a user-defined
copy-assignment operator removes any uncertainties. With such an
