diff --git a/include/fmt/core.h b/include/fmt/core.h
index 0944973e..5da04ed0 100644
--- a/include/fmt/core.h
+++ b/include/fmt/core.h
@@ -24,7 +24,7 @@
 # define FMT_HAS_FEATURE(x) 0
 #endif
 
-#if defined(__has_include)
+#ifdef __has_include
 # define FMT_HAS_INCLUDE(x) __has_include(x)
 #else
 # define FMT_HAS_INCLUDE(x) 0
@@ -36,7 +36,7 @@
 # define FMT_GCC_VERSION 0
 #endif
 
-#if __cplusplus >= 201103L || defined __GXX_EXPERIMENTAL_CXX0X__
+#if __cplusplus >= 201103L || defined(__GXX_EXPERIMENTAL_CXX0X__)
 # define FMT_HAS_GXX_CXX11 FMT_GCC_VERSION
 #else
 # define FMT_HAS_GXX_CXX11 0
@@ -82,8 +82,6 @@
 # endif
 #endif
 
-#define FMT_USE_STRONG_ENUMS FMT_HAS_FEATURE(cxx_strong_enums)
-
 // Check if exceptions are disabled.
 #if defined(__GNUC__) && !defined(__EXCEPTIONS)
 # define FMT_EXCEPTIONS 0
diff --git a/test/container-test.cc b/test/container-test.cc
deleted file mode 100644
index 8cafb3d0..00000000
--- a/test/container-test.cc
+++ /dev/null
@@ -1,94 +0,0 @@
-/*
- Tests of container utilities
-
- Copyright (c) 2012 - 2016, Victor Zverovich
- All rights reserved.
-
- For the license information refer to format.h.
- */
-
-#include "fmt/container.h"
-#include "gtest/gtest.h"
-
-using fmt::internal::ContainerBuffer;
-
-TEST(ContainerBufferTest, Empty) {
-  std::string data;
-  ContainerBuffer<std::string> buffer(data);
-  EXPECT_EQ(0u, buffer.size());
-  EXPECT_EQ(0u, buffer.capacity());
-}
-
-TEST(ContainerBufferTest, Reserve) {
-  std::string data;
-  ContainerBuffer<std::string> buffer(data);
-  std::size_t capacity = std::string().capacity() + 10;
-  buffer.reserve(capacity);
-  EXPECT_EQ(0u, buffer.size());
-  EXPECT_EQ(capacity, buffer.capacity());
-}
-
-TEST(ContainerBufferTest, Resize) {
-  std::string data;
-  ContainerBuffer<std::string> buffer(data);
-  std::size_t size = std::string().capacity() + 10;
-  buffer.resize(size);
-  EXPECT_EQ(size, buffer.size());
-  EXPECT_EQ(size, buffer.capacity());
-}
-
-TEST(ContainerBufferTest, Append) {
-  std::string data("Why so");
-  const std::string serious(" serious");
-  ContainerBuffer<std::string> buffer(data);
-  buffer.append(serious.c_str(), serious.c_str() + serious.length());
-  EXPECT_EQ("Why so serious", data);
-  EXPECT_EQ(data.length(), buffer.size());
-}
-
-TEST(BasicContainerWriterTest, String) {
-  std::string data;
-  fmt::BasicContainerWriter<std::string> out(data);
-  out << "The answer is " << 42 << "\n";
-  EXPECT_EQ("The answer is 42\n", data);
-  EXPECT_EQ(17u, out.size());
-}
-
-TEST(BasicContainerWriterTest, WString) {
-  std::wstring data;
-  fmt::BasicContainerWriter<std::wstring> out(data);
-  out << "The answer is " << 42 << "\n";
-  EXPECT_EQ(L"The answer is 42\n", data);
-  EXPECT_EQ(17u, out.size());
-}
-
-TEST(BasicContainerWriterTest, Vector) {
-  std::vector<char> data;
-  fmt::BasicContainerWriter<std::vector<char> > out(data);
-  out << "The answer is " << 42 << "\n";
-  EXPECT_EQ(17u, data.size());
-  EXPECT_EQ(out.size(), data.size());
-}
-
-TEST(BasicContainerWriterTest, StringAppend) {
-  std::string data("The");
-  fmt::BasicContainerWriter<std::string> out(data);
-  EXPECT_EQ(3u, data.size());
-  EXPECT_EQ(3u, out.size());
-  out << " answer is " << 42 << "\n";
-  EXPECT_EQ("The answer is 42\n", data);
-  EXPECT_EQ(17u, out.size());
-}
-
-TEST(BasicContainerWriterTest, VectorAppend) {
-  std::vector<char> data;
-  data.push_back('T');
-  data.push_back('h');
-  data.push_back('e');
-  fmt::BasicContainerWriter<std::vector<char> > out(data);
-  EXPECT_EQ(3u, data.size());
-  EXPECT_EQ(3u, out.size());
-  out << " answer is " << 42 << "\n";
-  EXPECT_EQ(17u, data.size());
-  EXPECT_EQ(17u, out.size());
-}
diff --git a/test/format-test.cc b/test/format-test.cc
index 30b59fc2..54fe79ac 100644
--- a/test/format-test.cc
+++ b/test/format-test.cc
@@ -1508,7 +1508,7 @@ TEST(FormatTest, Enum) {
   EXPECT_EQ("0", fmt::format("{}", A));
 }
 
-#if FMT_USE_STRONG_ENUMS
+#if FMT_HAS_FEATURE(cxx_strong_enums)
 enum TestFixedEnum : short { B };
 
 TEST(FormatTest, FixedEnum) {