/*
- * Copyright 2016 Facebook, Inc.
+ * Copyright 2016-present Facebook, Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
namespace folly {
-// TLDR: Prefer using operator< for ordering. And when
-// a and b are equivalent objects, we return b to make
-// sorting stable.
-// See http://stepanovpapers.com/notes.pdf for details.
-template <typename T>
-constexpr T constexpr_max(T a, T b) {
- return b < a ? a : b;
-}
-
-// When a and b are equivalent objects, we return a to
-// make sorting stable.
-template <typename T>
-constexpr T constexpr_min(T a, T b) {
- return b < a ? b : a;
-}
-
-namespace detail {
-
-template <typename T, typename = void>
-struct constexpr_abs_helper {};
-
-template <typename T>
-struct constexpr_abs_helper<
- T,
- typename std::enable_if<std::is_floating_point<T>::value>::type> {
- static constexpr T go(T t) {
- return t < static_cast<T>(0) ? -t : t;
- }
-};
-
-template <typename T>
-struct constexpr_abs_helper<
- T,
- typename std::enable_if<
- std::is_integral<T>::value && !std::is_same<T, bool>::value &&
- std::is_unsigned<T>::value>::type> {
- static constexpr T go(T t) {
- return t;
- }
-};
-
-template <typename T>
-struct constexpr_abs_helper<
- T,
- typename std::enable_if<
- std::is_integral<T>::value && !std::is_same<T, bool>::value &&
- std::is_signed<T>::value>::type> {
- static constexpr typename std::make_unsigned<T>::type go(T t) {
- return t < static_cast<T>(0) ? -t : t;
- }
-};
-} // namespace detail
-
-template <typename T>
-constexpr auto constexpr_abs(T t)
- -> decltype(detail::constexpr_abs_helper<T>::go(t)) {
- return detail::constexpr_abs_helper<T>::go(t);
-}
-
namespace detail {
template <typename Char>
constexpr size_t constexpr_strlen_internal(const Char* s, size_t len) {
return *s == Char(0) ? len : constexpr_strlen_internal(s + 1, len + 1);
}
-static_assert(constexpr_strlen_internal("123456789", 0) == 9,
- "Someone appears to have broken constexpr_strlen...");
+static_assert(
+ constexpr_strlen_internal("123456789", 0) == 9,
+ "Someone appears to have broken constexpr_strlen...");
} // namespace detail
template <typename Char>
constexpr size_t constexpr_strlen(const char* s) {
#if defined(__clang__)
return __builtin_strlen(s);
-#elif defined(_MSC_VER)
+#elif defined(_MSC_VER) || defined(__CUDACC__)
return detail::constexpr_strlen_internal(s, 0);
#else
return std::strlen(s);
#endif
}
-}
+} // namespace folly