From 5e382efa84cae56e4fb96b77438182b3a0f4439d Mon Sep 17 00:00:00 2001
From: Peter Dimov <pdimov@gmail.com>
Date: Fri, 1 Oct 2021 15:51:13 +0300
Subject: [PATCH] Fix std::ostream failure on libstdc++

---
 include/boost/core/type_name.hpp | 7 +++++++
 test/type_name_test.cpp          | 2 +-
 2 files changed, 8 insertions(+), 1 deletion(-)

diff --git a/include/boost/core/type_name.hpp b/include/boost/core/type_name.hpp
index 93927fe..9a82dd3 100644
--- a/include/boost/core/type_name.hpp
+++ b/include/boost/core/type_name.hpp
@@ -21,6 +21,7 @@
 #include <utility>
 #include <cstdio>
 #include <cstddef>
+#include <iosfwd>
 #if !defined(BOOST_NO_CXX17_HDR_STRING_VIEW)
 # include <string_view>
 #endif
@@ -501,6 +502,12 @@ template<template<class Ch, class Tr> class L, class Ch> std::string type_name(
     return tn + '<' + type_name( tn_identity<Ch>() ) + '>';
 }
 
+// needed for libstdc++
+inline std::string type_name( tn_identity<std::ostream> )
+{
+    return "std::ostream";
+}
+
 #if !defined(BOOST_NO_CXX17_HDR_STRING_VIEW)
 
 inline std::string type_name( tn_identity<std::string_view> )
diff --git a/test/type_name_test.cpp b/test/type_name_test.cpp
index 61132cd..6ab08f5 100644
--- a/test/type_name_test.cpp
+++ b/test/type_name_test.cpp
@@ -193,7 +193,7 @@ int main()
 
 #endif
 
-    TEST(std::basic_ostream<char>);
+    TEST(std::ostream);
     TEST(std::basic_ostream<wchar_t>);
 
 #if !defined(BOOST_NO_CXX17_HDR_STRING_VIEW)