From 987514761eb29e3ce9d9ec93b3a2ca6cfeb77fd9 Mon Sep 17 00:00:00 2001
From: Victor Zverovich <victor.zverovich@gmail.com>
Date: Wed, 22 Aug 2018 07:40:06 -0700
Subject: [PATCH] Make convert_to_int public (#818)

---
 CMakeLists.txt        | 16 ++++++++++------
 include/fmt/core.h    | 14 +++++++-------
 include/fmt/ostream.h | 18 +++++++++---------
 test/core-test.cc     |  8 ++++----
 test/ostream-test.cc  |  4 ++--
 5 files changed, 32 insertions(+), 28 deletions(-)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index fe1a6f9d..3d2d59e8 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -98,7 +98,7 @@ if(CMAKE_CXX_COMPILER_ID MATCHES "Clang")
       -Wno-c++98-compat -Wno-c++98-compat-pedantic -Wno-reserved-id-macro
       -Wno-global-constructors -Wno-disabled-macro-expansion
       -Wno-switch-enum -Wno-documentation-unknown-command
-      -Wno-gnu-string-literal-operator-template -Wno-unused-member-function
+      -Wno-unused-member-function
       -Wno-format-nonliteral -Wno-missing-noreturn -Wno-undefined-func-template
       -Wno-shadow -Wno-sign-conversion -Wno-used-but-marked-unused
       -Wno-covered-switch-default -Wno-missing-variable-declarations
@@ -108,13 +108,17 @@ if(CMAKE_CXX_COMPILER_ID MATCHES "Clang")
 
   check_cxx_compiler_flag(-Wno-zero-as-null-pointer-constant HAS_NULLPTR_WARNING)
   if (HAS_NULLPTR_WARNING)
-    set(PEDANTIC_COMPILE_FLAGS ${PEDANTIC_COMPILE_FLAGS} -Wno-zero-as-null-pointer-constant)
+    set(PEDANTIC_COMPILE_FLAGS ${PEDANTIC_COMPILE_FLAGS}
+        -Wno-zero-as-null-pointer-constant)
   endif ()
 
-  check_cxx_compiler_flag(-Wno-gnu-string-literal-operator-template HAS_GNU_UDL_WARNING)
-  if (HAS_GNU_UDL_WARNING)
-    set(PEDANTIC_COMPILE_FLAGS ${PEDANTIC_COMPILE_FLAGS} -Wno-gnu-string-literal-operator-template)
-  endif ()
+endif ()
+
+check_cxx_compiler_flag(
+  -Wno-gnu-string-literal-operator-template HAS_GNU_UDL_WARNING)
+if (HAS_GNU_UDL_WARNING)
+  set(PEDANTIC_COMPILE_FLAGS ${PEDANTIC_COMPILE_FLAGS}
+      -Wno-gnu-string-literal-operator-template)
 endif ()
 
 if (MSVC)
diff --git a/include/fmt/core.h b/include/fmt/core.h
index 1adca5ae..dbcaad90 100644
--- a/include/fmt/core.h
+++ b/include/fmt/core.h
@@ -341,6 +341,13 @@ class basic_format_args;
 template <typename T, typename Char = char, typename Enable = void>
 struct formatter;
 
+template <typename T, typename Char, typename Enable = void>
+struct convert_to_int {
+  enum {
+    value = !std::is_arithmetic<T>::value && std::is_convertible<T, int>::value
+  };
+};
+
 namespace internal {
 
 /** A contiguous memory buffer with an optional growing ability. */
@@ -490,13 +497,6 @@ FMT_CONSTEXPR bool is_arithmetic(type t) {
   return t > internal::none_type && t <= internal::last_numeric_type;
 }
 
-template <typename T, typename Char, bool ENABLE = true>
-struct convert_to_int {
-  enum {
-    value = !std::is_arithmetic<T>::value && std::is_convertible<T, int>::value
-  };
-};
-
 template <typename Char>
 struct string_value {
   const Char *value;
diff --git a/include/fmt/ostream.h b/include/fmt/ostream.h
index 0b1a4a02..e467f1ae 100644
--- a/include/fmt/ostream.h
+++ b/include/fmt/ostream.h
@@ -71,15 +71,6 @@ class is_streamable {
   static const bool value = result::value;
 };
 
-// Disable conversion to int if T has an overloaded operator<< which is a free
-// function (not a member of std::ostream).
-template <typename T, typename Char>
-class convert_to_int<T, Char, true> {
- public:
-  static const bool value =
-    convert_to_int<T, Char, false>::value && !is_streamable<T, Char>::value;
-};
-
 // Write the content of buf to os.
 template <typename Char>
 void write(std::basic_ostream<Char> &os, basic_buffer<Char> &buf) {
@@ -106,6 +97,15 @@ void format_value(basic_buffer<Char> &buffer, const T &value) {
 }
 }  // namespace internal
 
+// Disable conversion to int if T has an overloaded operator<< which is a free
+// function (not a member of std::ostream).
+template <typename T, typename Char>
+struct convert_to_int<T, Char, void> {
+  static const bool value =
+    convert_to_int<T, Char, int>::value &&
+    !internal::is_streamable<T, Char>::value;
+};
+
 // Formats an object of type T that has an overloaded ostream operator<<.
 template <typename T, typename Char>
 struct formatter<T, Char,
diff --git a/test/core-test.cc b/test/core-test.cc
index 12500729..06e63689 100644
--- a/test/core-test.cc
+++ b/test/core-test.cc
@@ -851,15 +851,15 @@ TEST(UtilTest, ReportWindowsError) {
 enum TestEnum2 {};
 
 TEST(UtilTest, ConvertToInt) {
-  EXPECT_FALSE((fmt::internal::convert_to_int<char, char>::value));
-  EXPECT_FALSE((fmt::internal::convert_to_int<const char *, char>::value));
-  EXPECT_TRUE((fmt::internal::convert_to_int<TestEnum2, char>::value));
+  EXPECT_FALSE((fmt::convert_to_int<char, char>::value));
+  EXPECT_FALSE((fmt::convert_to_int<const char *, char>::value));
+  EXPECT_TRUE((fmt::convert_to_int<TestEnum2, char>::value));
 }
 
 #if FMT_USE_ENUM_BASE
 enum TestEnum : char {TestValue};
 TEST(UtilTest, IsEnumConvertibleToInt) {
-  EXPECT_TRUE((fmt::internal::convert_to_int<TestEnum, char>::value));
+  EXPECT_TRUE((fmt::convert_to_int<TestEnum, char>::value));
 }
 #endif
 
diff --git a/test/ostream-test.cc b/test/ostream-test.cc
index 0f6bb793..96f6066c 100644
--- a/test/ostream-test.cc
+++ b/test/ostream-test.cc
@@ -37,10 +37,10 @@ static std::wostream &operator<<(std::wostream &os, TestEnum) {
 enum TestEnum2 {A};
 
 TEST(OStreamTest, Enum) {
-  EXPECT_FALSE((fmt::internal::convert_to_int<TestEnum, char>::value));
+  EXPECT_FALSE((fmt::convert_to_int<TestEnum, char>::value));
   EXPECT_EQ("TestEnum", fmt::format("{}", TestEnum()));
   EXPECT_EQ("0", fmt::format("{}", A));
-  EXPECT_FALSE((fmt::internal::convert_to_int<TestEnum, wchar_t>::value));
+  EXPECT_FALSE((fmt::convert_to_int<TestEnum, wchar_t>::value));
   EXPECT_EQ(L"TestEnum", fmt::format(L"{}", TestEnum()));
   EXPECT_EQ(L"0", fmt::format(L"{}", A));
 }