Add detail/snprintf.hpp

test/CMakeLists.txt

@@ -87,3 +87,5 @@ boost_test(TYPE run SOURCES cygwin_error_test.cpp)
 boost_test(TYPE run SOURCES linux_error_test.cpp)
 
 boost_test(TYPE link SOURCES errc_test3.cpp)
+
+boost_test(TYPE run SOURCES snprintf_test.cpp)

test/Jamfile.v2

@@ -91,3 +91,5 @@ run cygwin_error_test.cpp ;
 run linux_error_test.cpp ;
 
 link errc_test3.cpp ;
+
+run snprintf_test.cpp ;

test/snprintf_test.cpp

@@ -0,0 +1,60 @@
+// Copyright 2021 Peter Dimov.
+// Distributed under the Boost Software License, Version 1.0.
+// http://www.boost.org/LICENSE_1_0.txt
+
+#include <boost/system/detail/snprintf.hpp>
+#include <boost/core/lightweight_test.hpp>
+
+int main()
+{
+    {
+        char buffer[ 64 ];
+        boost::system::detail::snprintf( buffer, sizeof(buffer), "...%s...%d...", "xy", 151 );
+
+        BOOST_TEST_CSTR_EQ( buffer, "...xy...151..." );
+    }
+
+    {
+        char buffer[ 64 ];
+        boost::system::detail::snprintf( buffer, sizeof(buffer), "...%s...%d...", "xy", 151 );
+
+        BOOST_TEST_CSTR_EQ( buffer, "...xy...151..." );
+    }
+
+    {
+        char buffer[ 15 ];
+        boost::system::detail::snprintf( buffer, sizeof(buffer), "...%s...%d...", "xy", 151 );
+
+        BOOST_TEST_CSTR_EQ( buffer, "...xy...151..." );
+    }
+
+    {
+        char buffer[ 14 ];
+        boost::system::detail::snprintf( buffer, sizeof(buffer), "...%s...%d...", "xy", 151 );
+
+        BOOST_TEST_CSTR_EQ( buffer, "...xy...151.." );
+    }
+
+    {
+        char buffer[ 5 ];
+        boost::system::detail::snprintf( buffer, sizeof(buffer), "...%s...%d...", "xy", 151 );
+
+        BOOST_TEST_CSTR_EQ( buffer, "...x" );
+    }
+
+    {
+        char buffer[ 1 ];
+        boost::system::detail::snprintf( buffer, sizeof(buffer), "...%s...%d...", "xy", 151 );
+
+        BOOST_TEST_CSTR_EQ( buffer, "" );
+    }
+
+    {
+        char buffer[ 1 ] = { 'Q' };
+        boost::system::detail::snprintf( buffer, 0, "...%s...%d...", "xy", 151 );
+
+        BOOST_TEST_EQ( buffer[0], 'Q' );
+    }
+
+    return boost::report_errors();
+}