utils: drop operator<< for pretty printers

since all callers of these operators have switched to fmt formatters.
let's drop them. the tests are updated accordingly.

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

test/boost/pretty_printers_test.cc

@@ -9,7 +9,6 @@
 #define BOOST_TEST_MODULE utils
 
 #include <iterator>
-#include <sstream>
 #include <boost/test/unit_test.hpp>
 #include "utils/pretty_printers.hh"
 
@@ -29,14 +28,9 @@ BOOST_AUTO_TEST_CASE(test_print_data_size) {
         {10'000'000'000'000'000'000ULL, "10000PB"},
     };
     for (auto [n, expected] : sizes) {
-        std::stringstream out;
-        out << utils::pretty_printed_data_size{n};
-        auto actual = out.str();
+        std::string actual;
+        fmt::format_to(std::back_inserter(actual), "{}", utils::pretty_printed_data_size{n});
         BOOST_CHECK_EQUAL(actual, expected);
-
-        std::string s;
-        fmt::format_to(std::back_inserter(s), "{}", utils::pretty_printed_data_size{n});
-        BOOST_CHECK_EQUAL(s, expected);
     }
 }
 
@@ -54,13 +48,8 @@ BOOST_AUTO_TEST_CASE(test_print_throughput) {
         {10'000'000ULL, 0.5F, "20MB/s"},
     };
     for (auto [n, seconds, expected] : sizes) {
-        std::stringstream out;
-        out << utils::pretty_printed_throughput{n, std::chrono::duration<float>(seconds)};
-        auto actual = out.str();
+        std::string actual;
+        fmt::format_to(std::back_inserter(actual), "{}", utils::pretty_printed_throughput{n, std::chrono::duration<float>(seconds)});
         BOOST_CHECK_EQUAL(actual, expected);
-
-        std::string s;
-        fmt::format_to(std::back_inserter(s), "{}", utils::pretty_printed_throughput{n, std::chrono::duration<float>(seconds)});
-        BOOST_CHECK_EQUAL(s, expected);
     }
 }

utils/pretty_printers.cc

@@ -7,7 +7,6 @@
  */
 
 #include "pretty_printers.hh"
-#include <fmt/ostream.h>
 #include <tuple>
 
 template <typename Suffixes>
@@ -82,17 +81,3 @@ auto fmt::formatter<utils::pretty_printed_throughput>::format<fmt::basic_format_
     const utils::pretty_printed_throughput&,
     fmt::basic_format_context<std::back_insert_iterator<std::string>, char>& ctx) const
     -> decltype(ctx.out());
-
-namespace utils {
-
-std::ostream& operator<<(std::ostream& os, pretty_printed_data_size data) {
-    fmt::print(os, "{}", data);
-    return os;
-}
-
-std::ostream& operator<<(std::ostream& os, pretty_printed_throughput tp) {
-    fmt::print(os, "{}", tp);
-    return os;
-}
-
-}

utils/pretty_printers.hh

@@ -9,7 +9,6 @@
 #pragma once
 
 #include <chrono>
-#include <ostream>
 #include <fmt/core.h>
 
 namespace utils {
@@ -19,7 +18,6 @@ class pretty_printed_data_size {
 public:
     pretty_printed_data_size(uint64_t size) : _size(size) {}
 
-    friend std::ostream& operator<<(std::ostream&, pretty_printed_data_size);
     friend fmt::formatter<pretty_printed_data_size>;
 };
 
@@ -29,7 +27,6 @@ class pretty_printed_throughput {
 public:
     pretty_printed_throughput(uint64_t size, std::chrono::duration<float> dur) : _size(size), _duration(std::move(dur)) {}
 
-    friend std::ostream& operator<<(std::ostream&, pretty_printed_throughput);
     friend fmt::formatter<pretty_printed_throughput>;
 };