in C++20, compiler generate operator!=() if the corresponding
operator==() is already defined, the language now understands
that the comparison is symmetric in the new standard.
fortunately, our operator!=() is always equivalent to
`! operator==()`, this matches the behavior of the default
generated operator!=(). so, in this change, all `operator!=`
are removed.
in addition to the defaulted operator!=, C++20 also brings to us
the defaulted operator==() -- it is able to generated the
operator==() if the member-wise lexicographical comparison.
under some circumstances, this is exactly what we need. so,
in this change, if the operator==() is also implemented as
a lexicographical comparison of all memeber variables of the
class/struct in question, it is implemented using the default
generated one by removing its body and mark the function as
`default`. moreover, if the class happen to have other comparison
operators which are implemented using lexicographical comparison,
the default generated `operator<=>` is used in place of
the defaulted `operator==`.
sometimes, we fail to mark the operator== with the `const`
specifier, in this change, to fulfil the need of C++ standard,
and to be more correct, the `const` specifier is added.
also, to generate the defaulted operator==, the operand should
be `const class_name&`, but it is not always the case, in the
class of `version`, we use `version` as the parameter type, to
fulfill the need of the C++ standard, the parameter type is
changed to `const version&` instead. this does not change
the semantic of the comparison operator. and is a more idiomatic
way to pass non-trivial struct as function parameters.
please note, because in C++20, both operator= and operator<=> are
symmetric, some of the operators in `multiprecision` are removed.
they are the symmetric form of the another variant. if they were
not removed, compiler would, for instance, find ambiguous
overloaded operator '=='.
this change is a cleanup to modernize the code base with C++20
features.
Signed-off-by: Kefu Chai <kefu.chai@scylladb.com>
Closes#13687
Instead of lengthy blurbs, switch to single-line, machine-readable
standardized (https://spdx.dev) license identifiers. The Linux kernel
switched long ago, so there is strong precedent.
Three cases are handled: AGPL-only, Apache-only, and dual licensed.
For the latter case, I chose (AGPL-3.0-or-later and Apache-2.0),
reasoning that our changes are extensive enough to apply our license.
The changes we applied mechanically with a script, except to
licenses/README.md.
Closes#9937
C++20 makes string literals defined with u8"blah" return a new
char8_t type, which is sensible but noisy here.
Adjust for it by dropping an unneeded u8 in one place, and adding a
cast in another.
Message-Id: <20200512104515.137459-1-avi@scylladb.com>
Replace stdx::optional and stdx::string_view with the C++ std
counterparts.
Some instances of boost::variant were also replaced with std::variant,
namely those that called seastar::visit.
Scylla now requires GCC 8 to compile.
Signed-off-by: Duarte Nunes <duarte@scylladb.com>
Message-Id: <20190108111141.5369-1-duarte@scylladb.com>
* seastar d152f2d...c1e0e5d (6):
> scripts: perftune.py: properly merge parameters from the command line and the configuration file
> fmt: update to 5.2.1
> io_queue: only increment statistics when request is admitted
> Adds `read_first_line.cc` and `read_first_line.hh` to CMake.
> fstream: remove default extent allocation hint
> core/semaphore: Change the access of semaphore_units main ctor
Due to a compile-time fight between fmt and boost::multiprecision, a
lexical_cast was added to mediate.
sprint("%s", var) no longer accepts numeric values, so some sprint()s were
converted to format() calls. Since more may be lurking we'll need to remove
all sprint() calls.
Signed-off-by: Duarte Nunes <duarte@scylladb.com>
Cassandra 3.10 added the `duration` type [1], intended to manipulate date-time
values with offsets (for example, `now() - 2y3h`).
The full implementation of the `duration` type in Scylla requires support
for version 5 of the binary protocol, which is not yet available.
In the meantime, this patch patch adds the implementation of the underlying type
for the eventual `duration` type. Included is also the ported test suite from
the reference implementation and additional tests.
Related to #2240.
[1] https://issues.apache.org/jira/browse/CASSANDRA-11873
Signed-off-by: Jesse Haber-Kucharsky <jhaberku@scylladb.com>
Message-Id: <b1e481da103efee82106bf31f261c5a1f4f8d9ca.1499885803.git.jhaberku@scylladb.com>
