/*
- * Copyright 2016 Facebook, Inc.
+ * Copyright 2017 Facebook, Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
#include <bits/c++config.h>
#endif
-#include <boost/type_traits.hpp>
-
#define FOLLY_CREATE_HAS_MEMBER_TYPE_TRAITS(classname, type_name) \
template <typename TTheClass_> \
struct classname##__folly_traits_impl__ { \
template <typename UTheClass_> \
- static std::true_type test(typename UTheClass_::type_name*); \
+ static constexpr bool test(typename UTheClass_::type_name*) { \
+ return true; \
+ } \
template <typename> \
- static std::false_type test(...); \
+ static constexpr bool test(...) { \
+ return false; \
+ } \
}; \
template <typename TTheClass_> \
- using classname = decltype( \
+ using classname = typename std::conditional< \
classname##__folly_traits_impl__<TTheClass_>::template test<TTheClass_>( \
- nullptr))
+ nullptr), \
+ std::true_type, \
+ std::false_type>::type;
#define FOLLY_CREATE_HAS_MEMBER_FN_TRAITS_IMPL(classname, func_name, cv_qual) \
template <typename TTheClass_, typename RTheReturn_, typename... TTheArgs_> \
namespace folly {
+/***
+ * _t
+ *
+ * Instead of:
+ *
+ * using decayed = typename std::decay<T>::type;
+ *
+ * With the C++14 standard trait aliases, we could use:
+ *
+ * using decayed = std::decay_t<T>;
+ *
+ * Without them, we could use:
+ *
+ * using decayed = _t<std::decay<T>>;
+ *
+ * Also useful for any other library with template types having dependent
+ * member types named `type`, like the standard trait types.
+ */
+template <typename T>
+using _t = typename T::type;
+
+/**
+ * void_t
+ *
+ * A type alias for `void`. `void_t` is useful for controling class-template
+ * partial specialization.
+ *
+ * Example:
+ *
+ * // has_value_type<T>::value is true if T has a nested type `value_type`
+ * template <class T, class = void>
+ * struct has_value_type
+ * : std::false_type {};
+ *
+ * template <class T>
+ * struct has_value_type<T, folly::void_t<typename T::value_type>>
+ * : std::true_type {};
+ */
+#if defined(__cpp_lib_void_t) || defined(_MSC_VER)
+
+/* using override */ using std::void_t;
+
+#else // defined(__cpp_lib_void_t) || defined(_MSC_VER)
+
+namespace traits_detail {
+template <class...>
+struct void_t_ {
+ using type = void;
+};
+} // namespace traits_detail
+
+template <class... Ts>
+using void_t = _t<traits_detail::void_t_<Ts...>>;
+
+#endif // defined(__cpp_lib_void_t) || defined(_MSC_VER)
+
/**
* IsRelocatable<T>::value describes the ability of moving around
* memory a value of type T by using memcpy (as opposed to the
IsLessThanComparable;
namespace traits_detail_IsNothrowSwappable {
-#if defined(_MSC_VER) || defined(__cpp_lib_is_swappable)
-// MSVC already implements the C++17 P0185R1 proposal which
-// adds std::is_nothrow_swappable, so use it instead.
+#if defined(__cpp_lib_is_swappable) || (_CPPLIB_VER && _HAS_CXX17)
+// MSVC 2015+ already implements the C++17 P0185R1 proposal which
+// adds std::is_nothrow_swappable, so use it instead if C++17 mode
+// is enabled.
template <typename T>
using IsNothrowSwappable = std::is_nothrow_swappable<T>;
+#elif _CPPLIB_VER
+// MSVC 2015+ defines the base even if C++17 is disabled, and
+// MSVC 2015 has issues with our fallback implementation due to
+// over-eager evaluation of noexcept.
+template <typename T>
+using IsNothrowSwappable = std::_Is_nothrow_swappable<T>;
#else
/* using override */ using std::swap;
struct IsRelocatable< __VA_ARGS__ > : std::true_type {};
/**
- * Use this macro ONLY inside namespace boost. When using it with a
- * regular type, use it like this:
- *
- * // Make sure you're at namespace ::boost scope
- * template<> FOLLY_ASSUME_HAS_NOTHROW_CONSTRUCTOR(MyType)
- *
- * When using it with a template type, use it like this:
- *
- * // Make sure you're at namespace ::boost scope
- * template<class T1, class T2>
- * FOLLY_ASSUME_HAS_NOTHROW_CONSTRUCTOR(MyType<T1, T2>)
- */
-#define FOLLY_ASSUME_HAS_NOTHROW_CONSTRUCTOR(...) \
- struct has_nothrow_constructor< __VA_ARGS__ > : ::boost::true_type {};
-
-/**
- * The FOLLY_ASSUME_FBVECTOR_COMPATIBLE* macros below encode two
- * assumptions: first, that the type is relocatable per IsRelocatable
- * above, and that it has a nothrow constructor. Most types can be
- * assumed to satisfy both conditions, but it is the responsibility of
- * the user to state that assumption. User-defined classes will not
- * work with fbvector (see FBVector.h) unless they state this
- * combination of properties.
+ * The FOLLY_ASSUME_FBVECTOR_COMPATIBLE* macros below encode the
+ * assumption that the type is relocatable per IsRelocatable
+ * above. Many types can be assumed to satisfy this condition, but
+ * it is the responsibility of the user to state that assumption.
+ * User-defined classes will not be optimized for use with
+ * fbvector (see FBVector.h) unless they state that assumption.
*
* Use FOLLY_ASSUME_FBVECTOR_COMPATIBLE with regular types like this:
*
*/
// Use this macro ONLY at global level (no namespace)
-#define FOLLY_ASSUME_FBVECTOR_COMPATIBLE(...) \
- namespace folly { template<> FOLLY_ASSUME_RELOCATABLE(__VA_ARGS__) } \
- namespace boost { \
- template<> FOLLY_ASSUME_HAS_NOTHROW_CONSTRUCTOR(__VA_ARGS__) }
+#define FOLLY_ASSUME_FBVECTOR_COMPATIBLE(...) \
+ namespace folly { \
+ template <> \
+ FOLLY_ASSUME_RELOCATABLE(__VA_ARGS__) \
+ }
// Use this macro ONLY at global level (no namespace)
-#define FOLLY_ASSUME_FBVECTOR_COMPATIBLE_1(...) \
- namespace folly { \
- template <class T1> FOLLY_ASSUME_RELOCATABLE(__VA_ARGS__<T1>) } \
- namespace boost { \
- template <class T1> FOLLY_ASSUME_HAS_NOTHROW_CONSTRUCTOR(__VA_ARGS__<T1>) }
+#define FOLLY_ASSUME_FBVECTOR_COMPATIBLE_1(...) \
+ namespace folly { \
+ template <class T1> \
+ FOLLY_ASSUME_RELOCATABLE(__VA_ARGS__<T1>) \
+ }
// Use this macro ONLY at global level (no namespace)
-#define FOLLY_ASSUME_FBVECTOR_COMPATIBLE_2(...) \
- namespace folly { \
- template <class T1, class T2> \
- FOLLY_ASSUME_RELOCATABLE(__VA_ARGS__<T1, T2>) } \
- namespace boost { \
- template <class T1, class T2> \
- FOLLY_ASSUME_HAS_NOTHROW_CONSTRUCTOR(__VA_ARGS__<T1, T2>) }
+#define FOLLY_ASSUME_FBVECTOR_COMPATIBLE_2(...) \
+ namespace folly { \
+ template <class T1, class T2> \
+ FOLLY_ASSUME_RELOCATABLE(__VA_ARGS__<T1, T2>) \
+ }
// Use this macro ONLY at global level (no namespace)
-#define FOLLY_ASSUME_FBVECTOR_COMPATIBLE_3(...) \
- namespace folly { \
- template <class T1, class T2, class T3> \
- FOLLY_ASSUME_RELOCATABLE(__VA_ARGS__<T1, T2, T3>) } \
- namespace boost { \
- template <class T1, class T2, class T3> \
- FOLLY_ASSUME_HAS_NOTHROW_CONSTRUCTOR(__VA_ARGS__<T1, T2, T3>) }
+#define FOLLY_ASSUME_FBVECTOR_COMPATIBLE_3(...) \
+ namespace folly { \
+ template <class T1, class T2, class T3> \
+ FOLLY_ASSUME_RELOCATABLE(__VA_ARGS__<T1, T2, T3>) \
+ }
// Use this macro ONLY at global level (no namespace)
-#define FOLLY_ASSUME_FBVECTOR_COMPATIBLE_4(...) \
- namespace folly { \
- template <class T1, class T2, class T3, class T4> \
- FOLLY_ASSUME_RELOCATABLE(__VA_ARGS__<T1, T2, T3, T4>) } \
- namespace boost { \
- template <class T1, class T2, class T3, class T4> \
- FOLLY_ASSUME_HAS_NOTHROW_CONSTRUCTOR(__VA_ARGS__<T1, T2, T3, T4>) }
+#define FOLLY_ASSUME_FBVECTOR_COMPATIBLE_4(...) \
+ namespace folly { \
+ template <class T1, class T2, class T3, class T4> \
+ FOLLY_ASSUME_RELOCATABLE(__VA_ARGS__<T1, T2, T3, T4>) \
+ }
/**
* Instantiate FOLLY_ASSUME_FBVECTOR_COMPATIBLE for a few types. It is
FOLLY_NAMESPACE_STD_END
-namespace boost {
-
-template <class T> class shared_ptr;
-
-template <class T, class U>
-struct has_nothrow_constructor< std::pair<T, U> >
- : std::integral_constant<bool,
- has_nothrow_constructor<T>::value &&
- has_nothrow_constructor<U>::value> {};
-
-} // namespace boost
-
namespace folly {
// STL commonly-used types
// types) that violate -Wsign-compare and/or -Wbool-compare so suppress them
// in order to not prevent all calling code from using it.
FOLLY_PUSH_WARNING
-FOLLY_GCC_DISABLE_WARNING(sign-compare)
+FOLLY_GCC_DISABLE_WARNING("-Wsign-compare")
#if __GNUC_PREREQ(5, 0)
-FOLLY_GCC_DISABLE_WARNING(bool-compare)
+FOLLY_GCC_DISABLE_WARNING("-Wbool-compare")
#endif
FOLLY_MSVC_DISABLE_WARNING(4388) // sign-compare
FOLLY_MSVC_DISABLE_WARNING(4804) // bool-compare
// Assume nothing when compiling with MSVC.
#ifndef _MSC_VER
-// gcc-5.0 changed string's implementation in libgcc to be non-relocatable
-#if __GNUC__ < 5
+// gcc-5.0 changed string's implementation in libstdc++ to be non-relocatable
+#if !_GLIBCXX_USE_CXX11_ABI
FOLLY_ASSUME_FBVECTOR_COMPATIBLE_3(std::basic_string)
#endif
FOLLY_ASSUME_FBVECTOR_COMPATIBLE_2(std::vector)
FOLLY_ASSUME_FBVECTOR_COMPATIBLE_2(std::unique_ptr)
FOLLY_ASSUME_FBVECTOR_COMPATIBLE_1(std::shared_ptr)
FOLLY_ASSUME_FBVECTOR_COMPATIBLE_1(std::function)
-
-// Boost
-FOLLY_ASSUME_FBVECTOR_COMPATIBLE_1(boost::shared_ptr)
#endif
/* Some combinations of compilers and C++ libraries make __int128 and
projects / folly.git / blobdiff