From effd732123fd47ae8547d6d4834bf77227131061 Mon Sep 17 00:00:00 2001
From: Alexey Ochapov <alexez@alexez.com>
Date: Thu, 20 May 2021 23:17:18 +0300
Subject: [PATCH] add `fmt::print()` overload to support compiled format

---
 include/fmt/compile.h    | 14 ++++++++++++++
 include/fmt/format-inl.h | 12 +++++++++---
 include/fmt/format.h     |  4 ++++
 test/compile-test.cc     |  8 ++++++++
 4 files changed, 35 insertions(+), 3 deletions(-)

diff --git a/include/fmt/compile.h b/include/fmt/compile.h
index 718815357ea3..7b0ef8951b15 100644
--- a/include/fmt/compile.h
+++ b/include/fmt/compile.h
@@ -606,6 +606,20 @@ size_t formatted_size(const S& format_str, const Args&... args) {
   return format_to(detail::counting_iterator(), format_str, args...).count();
 }
 
+template <typename S, typename... Args,
+          FMT_ENABLE_IF(detail::is_compiled_string<S>::value)>
+void print(std::FILE* f, const S& format_str, const Args&... args) {
+  memory_buffer buffer;
+  format_to(std::back_inserter(buffer), format_str, args...);
+  detail::print_buffer(f, buffer);
+}
+
+template <typename S, typename... Args,
+          FMT_ENABLE_IF(detail::is_compiled_string<S>::value)>
+void print(const S& format_str, const Args&... args) {
+  print(stdout, format_str, args...);
+}
+
 #if FMT_USE_NONTYPE_TEMPLATE_PARAMETERS
 inline namespace literals {
 template <detail::fixed_string Str>
diff --git a/include/fmt/format-inl.h b/include/fmt/format-inl.h
index 93b7a90727eb..d26257aaeea3 100644
--- a/include/fmt/format-inl.h
+++ b/include/fmt/format-inl.h
@@ -2594,9 +2594,8 @@ extern "C" __declspec(dllimport) int __stdcall WriteConsoleW(  //
 }  // namespace detail
 #endif
 
-FMT_FUNC void vprint(std::FILE* f, string_view format_str, format_args args) {
-  memory_buffer buffer;
-  detail::vformat_to(buffer, format_str, args);
+namespace detail {
+FMT_FUNC void print_buffer(std::FILE* f, const memory_buffer& buffer) {
 #ifdef _WIN32
   auto fd = _fileno(f);
   if (_isatty(fd)) {
@@ -2613,6 +2612,13 @@ FMT_FUNC void vprint(std::FILE* f, string_view format_str, format_args args) {
 #endif
   detail::fwrite_fully(buffer.data(), 1, buffer.size(), f);
 }
+}  // namespace detail
+
+FMT_FUNC void vprint(std::FILE* f, string_view format_str, format_args args) {
+  memory_buffer buffer;
+  detail::vformat_to(buffer, format_str, args);
+  detail::print_buffer(f, buffer);
+}
 
 #ifdef _WIN32
 // Print assuming legacy (non-Unicode) encoding.
diff --git a/include/fmt/format.h b/include/fmt/format.h
index 0478ba0c9186..0616a598b4d4 100644
--- a/include/fmt/format.h
+++ b/include/fmt/format.h
@@ -783,6 +783,10 @@ template <typename T, size_t SIZE, typename Allocator>
 struct is_contiguous<basic_memory_buffer<T, SIZE, Allocator>> : std::true_type {
 };
 
+namespace detail {
+FMT_API void print_buffer(std::FILE*, const memory_buffer&);
+}
+
 /** A formatting error such as invalid format string. */
 FMT_CLASS_API
 class FMT_API format_error : public std::runtime_error {
diff --git a/test/compile-test.cc b/test/compile-test.cc
index 71eddc920e4f..58fd057d7b51 100644
--- a/test/compile-test.cc
+++ b/test/compile-test.cc
@@ -11,6 +11,7 @@
 
 #include "fmt/chrono.h"
 #include "gmock/gmock.h"
+#include "gtest-extra.h"
 
 TEST(iterator_test, counting_iterator) {
   auto it = fmt::detail::counting_iterator();
@@ -241,6 +242,13 @@ FMT_END_NAMESPACE
 TEST(compile_test, to_string_and_formatter) {
   fmt::format(FMT_COMPILE("{}"), to_stringable());
 }
+
+TEST(compile_test, print) {
+  EXPECT_WRITE(stdout, fmt::print(FMT_COMPILE("Don't {}!"), "panic"),
+               "Don't panic!");
+  EXPECT_WRITE(stderr, fmt::print(stderr, FMT_COMPILE("Don't {}!"), "panic"),
+               "Don't panic!");
+}
 #endif
 
 #if FMT_USE_NONTYPE_TEMPLATE_PARAMETERS