This reverts commit 3c54d5ec5e.
The reverted change fixed the FTBFS of the test in question with Clang 16,
which rightly stopped convert the LHS of `"hello" == sstring{"hello"}` to
the type of the type acceptable by the member operator even we have a
constructor for this conversion, like
class sstring {
public:
bar_t(const char*);
bool operator==(const sstring&) const;
bool operator!=(const sstring&) const;
};
because we have an operator!=, as per the draft of C++ standard
https://eel.is/c++draft/over.match.oper#4 :
> A non-template function or function template F named operator==
> is a rewrite target with first operand o unless a search for the
> name operator!= in the scope S from the instantiation context of
> the operator expression finds a function or function template
> that would correspond ([basic.scope.scope]) to F if its name were
> operator==, where S is the scope of the class type of o if F is a
> class member, and the namespace scope of which F is a member
> otherwise.
in 397f4b51c3, the seastar submodule was
updated. in which, we now have a dedicated overload for the `const char*`
case. so the compiler is now able to compile the expression like
`"hello" == sstring{"hello"}` in C++20 now.
so, in this change, the workaround is reverted.
Closes#14040
For unknown reasons, clang 16 rejects equality comparison
(operator==) where the left-hand-side is an std::string and the
right-hand-side is an sstring. gcc and older clang versions first
convert the left-hand-side to an sstring and then call the symmetric
equality operator.
I was able to hack sstring to support this assymetric comparison,
but the solution is quite convoluted, and it may be that it's clang
at fault here. So instead this patch eliminates the three cases where
it happened. With is applied, we can build with clang 16.
Closes#13893
It's unused.
Just in case, add a unit test case for using the fmt library to
format it (that includes fmt::to_string(std::initializer_list)).
Note that the existing to_string implementation
used square brackets to enclose the initializer_list
but the new, standardized form uses curly braces.
This doesn't break anything since to_string(initializer_list)
wasn't used.
Signed-off-by: Benny Halevy <bhalevy@scylladb.com>
As seen in https://github.com/scylladb/scylladb/issues/13146
the current implementation is not general enough
to provide print helpers for all kind of containers.
Modernize the implementation using templates based
on std::ranges::range and using fmt::join.
Extend unit test for formatting different types of ranges,
boost::transformed ranges, deque.
Fixes#13146
Signed-off-by: Benny Halevy <bhalevy@scylladb.com>
