From b643520c528fb3fc8e541cb1e743a83f660f5673 Mon Sep 17 00:00:00 2001
From: Thomas Novotny <tnovotny@web.de>
Date: Sun, 18 Nov 2018 21:44:09 +0100
Subject: [PATCH] add missing make_printf_args and make_wprintf_args to
 printf.h add minimal test for make_printf_args and make_wprintf_args to
 printf-test.cc

---
 include/fmt/printf.h | 27 +++++++++++++++++++++++++++
 test/printf-test.cc  | 16 ++++++++++++++++
 2 files changed, 43 insertions(+)

diff --git a/include/fmt/printf.h b/include/fmt/printf.h
index e8caecaa..4b0b692c 100644
--- a/include/fmt/printf.h
+++ b/include/fmt/printf.h
@@ -581,6 +581,33 @@ struct printf_context {
 typedef basic_format_args<printf_context<internal::buffer>::type> printf_args;
 typedef basic_format_args<printf_context<internal::wbuffer>::type> wprintf_args;
 
+typedef printf_context<internal::buffer>::type printf_char_context;
+typedef printf_context<internal::wbuffer>::type printf_wchar_context;
+
+
+/**
+  \rst
+  Constructs an `~fmt::format_arg_store` object that contains references to
+  arguments and can be implicitly converted to `~fmt::printf_args`. `Context`
+  can be omitted in which case it defaults to `~fmt::printf_char_context`.
+  \endrst
+ */
+template<typename Context=printf_char_context, typename... Args>
+inline format_arg_store<Context, Args...>
+  make_printf_args(const Args &... args) { return {args...}; }
+
+/**
+  \rst
+  Constructs an `~fmt::format_arg_store` object that contains references to
+  arguments and can be implicitly converted to `~fmt::wprintf_args`. `Context`
+  can be omitted in which case it defaults to `~fmt::printf_wchar_context`.
+  \endrst
+ */
+template<typename Context = printf_wchar_context, typename... Args>
+inline format_arg_store<Context, Args...>
+  make_wprintf_args(const Args &... args) { return {args...}; }
+
+
 template <typename S, typename Char = FMT_CHAR(S)>
 inline std::basic_string<Char>
 vsprintf(const S &format,
diff --git a/test/printf-test.cc b/test/printf-test.cc
index d3e222f2..c51e7f27 100644
--- a/test/printf-test.cc
+++ b/test/printf-test.cc
@@ -518,3 +518,19 @@ void check_format_string_regression(fmt::string_view s, const Args&... args) {
 TEST(PrintfTest, CheckFormatStringRegression) {
   check_format_string_regression("%c%s", 'x', "");
 }
+
+
+TEST(PrintfTest, VSPrintfMessageExample) {
+  EXPECT_EQ(
+      "[42] something happened",
+      fmt::vsprintf(
+          "[%d] %s happened", fmt::make_printf_args( 42, "something" ) ) );
+}
+
+
+TEST(PrintfTest, VSPrintfWMessageExample) {
+  EXPECT_EQ(
+      L"[42] something happened",
+      fmt::vsprintf(
+          L"[%d] %s happened", fmt::make_wprintf_args( 42, L"something" ) ) );
+}