bahman/scylla
1
0
Fork 0
Code Issues Pull Requests Actions 3 Packages Projects Releases Wiki Activity

api: specialize fmt::formatter<api::table_info>

Browse Source 
this is a part of a series to migrating from `operator<<(ostream&, ..)`
based formatting to fmtlib based formatting. the goal here is to enable
fmtlib to print `api::table_info` without the help of `operator<<`.

but the corresponding `operator<<()` is preserved in this change, as we
still have lots of callers relying on this << operator instorage_service.cc
where std::vector<table_info> is formatted using operator<<(ostream&, const Range&)
defined in to_string.hh. we could have used fmt/ranges.h to print the
std::vector<table_info>. but the combination of operator<<(ostream&, const Range&)
and FMT_DEPRECATED_OSTREAM renders this impossible. because
unlike the builtin range formatter specializations, the fallback formatter
synthesized from the operator<< does not have brackets defined for
the range printer. the brackets are used as the left and right marks
of the range, for instance, the array-alike containers are printed
like [1,2,3], while the tuple-alike containers are printed like
(1,2,3). once we are allowed to remove FMT_DEPRECATED_OSTREAM, we
should be able to use the builtin range formatter, and remove the
operator<< for api::table_info by then.

Refs #13245

Signed-off-by: Kefu Chai <kefu.chai@scylladb.com>

Closes #13975
This commit is contained in:
Kefu Chai
2023-05-22 15:37:19 +08:00
committed by Botond Dénes
parent 8efb5c30ce
commit 2fbcbc09b0
2 changed files with 11 additions and 1 deletions
Download Patch File Download Diff File Expand all files Collapse all files

7
api/storage_service.cc
View File

@@ -55,12 +55,17 @@ extern logging::logger apilog;
namespace std {
std::ostream& operator<<(std::ostream& os, const api::table_info& ti) {
fmt::print(os, "table{{name={}, id={}}}", ti.name, ti.id);
fmt::print(os, "{}", ti);
return os;
}
} // namespace std
auto fmt::formatter<api::table_info>::format(const api::table_info& ti,
fmt::format_context& ctx) const -> decltype(ctx.out()) {
return fmt::format_to(ctx.out(), "table{{name={}, id={}}}", ti.name, ti.id);
}
namespace api {
const locator::token_metadata& http_context::get_token_metadata() {

5
api/storage_service.hh
View File

@@ -85,3 +85,8 @@ namespace std {
std::ostream& operator<<(std::ostream& os, const api::table_info& ti);
} // namespace std
template <>
struct fmt::formatter<api::table_info> : fmt::formatter<std::string_view> {
auto format(const api::table_info&, fmt::format_context& ctx) const -> decltype(ctx.out());
};