Add default_logger() and default_verbose_logger()

include/cppast/parser.hpp

@@ -21,7 +21,8 @@ namespace cppast
     class diagnostic_logger
     {
     public:
-        diagnostic_logger() noexcept : verbose_(false)
+        /// \effects Creates it either as verbose or not.
+        explicit diagnostic_logger(bool is_verbose = false) noexcept : verbose_(is_verbose)
         {
         }
 
@@ -52,11 +53,20 @@ namespace cppast
         bool verbose_;
     };
 
+    /// \returns The default logger object.
+    type_safe::object_ref<const diagnostic_logger> default_logger() noexcept;
+
+    /// \returns The default verbose logger object.
+    type_safe::object_ref<const diagnostic_logger> default_verbose_logger() noexcept;
+
     /// A [cppast::diagnostic_logger]() that logs to `stderr`.
     ///
     /// It prints all diagnostics in an implementation-defined format.
     class stderr_diagnostic_logger final : public diagnostic_logger
     {
+    public:
+        using diagnostic_logger::diagnostic_logger;
+
     private:
         bool do_log(const char* source, const diagnostic& d) const override;
     };

src/parser.cpp

@@ -18,6 +18,18 @@ bool diagnostic_logger::log(const char* source, const diagnostic& d) const
     return do_log(source, d);
 }
 
+type_safe::object_ref<const diagnostic_logger> cppast::default_logger() noexcept
+{
+    static const stderr_diagnostic_logger logger(false);
+    return type_safe::ref(logger);
+}
+
+type_safe::object_ref<const diagnostic_logger> cppast::default_verbose_logger() noexcept
+{
+    static const stderr_diagnostic_logger logger(true);
+    return type_safe::ref(logger);
+}
+
 bool stderr_diagnostic_logger::do_log(const char* source, const diagnostic& d) const
 {
     auto loc = d.location.to_string();

test/test_parser.hpp

@@ -31,8 +31,7 @@ inline std::unique_ptr<cppast::cpp_file> parse_file(const cppast::cpp_entity_ind
     libclang_compile_config config;
     config.set_flags(cpp_standard::cpp_latest);
 
-    stderr_diagnostic_logger logger;
-    libclang_parser          p(type_safe::ref(logger));
+    libclang_parser p(default_logger());
 
     std::unique_ptr<cppast::cpp_file> result;
     REQUIRE_NOTHROW(result = p.parse(idx, name, config));