Better support for string_view

include/spdlog/common.h

@@ -56,6 +56,13 @@ using sink_ptr = std::shared_ptr<sinks::sink>;
 using sinks_init_list = std::initializer_list<sink_ptr>;
 using log_err_handler = std::function<void(const std::string &err_msg)>;
 
+// string_view type - either std::string_view or fmt::string_view (pre c++17)
+#if defined(FMT_USE_STD_STRING_VIEW)
+using string_view_type = std::string_view;
+#else
+using string_view_type = fmt::string_view;
+#endif
+
 #if defined(SPDLOG_NO_ATOMIC_LEVELS)
 using level_t = details::null_atomic_int;
 #else

include/spdlog/details/fmt_helper.h

@@ -14,9 +14,9 @@ namespace details {
 namespace fmt_helper {
 
 template<size_t Buffer_Size>
-inline fmt::string_view to_string_view(const fmt::basic_memory_buffer<char, Buffer_Size> &buf) SPDLOG_NOEXCEPT
+inline spdlog::string_view_type to_string_view(const fmt::basic_memory_buffer<char, Buffer_Size> &buf) SPDLOG_NOEXCEPT
 {
-    return fmt::string_view(buf.data(), buf.size());
+    return spdlog::string_view_type(buf.data(), buf.size());
 }
 template<size_t Buffer_Size1, size_t Buffer_Size2>
 inline void append_buf(const fmt::basic_memory_buffer<char, Buffer_Size1> &buf, fmt::basic_memory_buffer<char, Buffer_Size2> &dest)
@@ -26,7 +26,7 @@ inline void append_buf(const fmt::basic_memory_buffer<char, Buffer_Size1> &buf,
 }
 
 template<size_t Buffer_Size>
-inline void append_string_view(fmt::string_view view, fmt::basic_memory_buffer<char, Buffer_Size> &dest)
+inline void append_string_view(spdlog::string_view_type view, fmt::basic_memory_buffer<char, Buffer_Size> &dest)
 {
     auto *buf_ptr = view.data();
     if (buf_ptr != nullptr)

include/spdlog/details/log_msg.h

@@ -17,7 +17,7 @@ struct log_msg
 {
     log_msg() = default;
 
-    log_msg(const std::string *loggers_name, level::level_enum lvl, fmt::string_view view)
+    log_msg(const std::string *loggers_name, level::level_enum lvl, string_view_type view)
         : logger_name(loggers_name)
         , level(lvl)
 #ifndef SPDLOG_NO_DATETIME
@@ -44,7 +44,7 @@ struct log_msg
     mutable size_t color_range_start{0};
     mutable size_t color_range_end{0};
 
-    const fmt::string_view payload;
+    const string_view_type payload;
 };
 } // namespace details
 } // namespace spdlog

include/spdlog/details/pattern_formatter.h

@@ -39,7 +39,7 @@ class name_formatter : public flag_formatter
     void format(const details::log_msg &msg, const std::tm &, fmt::memory_buffer &dest) override
     {
         // fmt_helper::append_str(*msg.logger_name, dest);
-        fmt_helper::append_string_view(*msg.logger_name, dest);
+        fmt_helper::append_string_view(string_view_type(*msg.logger_name), dest);
     }
 };
 
@@ -49,6 +49,7 @@ class level_formatter : public flag_formatter
     void format(const details::log_msg &msg, const std::tm &, fmt::memory_buffer &dest) override
     {
         // fmt_helper::append_string_view(level::to_c_str(msg.level), dest);
+        spdlog::string_view_type t("SSSSSSS");
         fmt_helper::append_string_view(level::to_c_str(msg.level), dest);
     }
 };

include/spdlog/details/thread_pool.h

@@ -94,7 +94,7 @@ struct async_msg
     // copy into log_msg
     log_msg to_log_msg()
     {
-        log_msg msg(&worker_ptr->name(), level, fmt::string_view(raw.data(), raw.size()));
+        log_msg msg(&worker_ptr->name(), level, string_view_type(raw.data(), raw.size()));
         msg.time = time;
         msg.thread_id = thread_id;
         msg.msg_id = msg_id;