llvm-project/compiler-rt/lib/orc/adt.h

129 lines
4.0 KiB
C++

//===----------------------- adt.h - Handy ADTs -----------------*- C++ -*-===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
// This file is a part of the ORC runtime support library.
//
//===----------------------------------------------------------------------===//
#ifndef ORC_RT_ADT_H
#define ORC_RT_ADT_H
#include <cstring>
#include <limits>
#include <ostream>
#include <string>
namespace __orc_rt {
constexpr std::size_t dynamic_extent = std::numeric_limits<std::size_t>::max();
/// A substitute for std::span (and llvm::ArrayRef).
/// FIXME: Remove in favor of std::span once we can use c++20.
template <typename T, std::size_t Extent = dynamic_extent> class span {
public:
typedef T element_type;
typedef std::remove_cv<T> value_type;
typedef std::size_t size_type;
typedef std::ptrdiff_t difference_type;
typedef T *pointer;
typedef const T *const_pointer;
typedef T &reference;
typedef const T &const_reference;
typedef pointer iterator;
static constexpr std::size_t extent = Extent;
constexpr span() noexcept = default;
constexpr span(T *first, size_type count) noexcept
: Data(first), Size(count) {}
template <std::size_t N>
constexpr span(T (&arr)[N]) noexcept : Data(&arr[0]), Size(N) {}
constexpr iterator begin() const noexcept { return Data; }
constexpr iterator end() const noexcept { return Data + Size; }
constexpr pointer data() const noexcept { return Data; }
constexpr reference operator[](size_type idx) const { return Data[idx]; }
constexpr size_type size() const noexcept { return Size; }
constexpr bool empty() const noexcept { return Size == 0; }
private:
T *Data = nullptr;
size_type Size = 0;
};
/// A substitue for std::string_view (and llvm::StringRef).
/// FIXME: Remove in favor of std::string_view once we have c++17.
class string_view {
public:
typedef char value_type;
typedef char *pointer;
typedef const char *const_pointer;
typedef char &reference;
typedef const char &const_reference;
typedef std::size_t size_type;
typedef std::ptrdiff_t difference_type;
typedef const_pointer const_iterator;
typedef const_iterator iterator;
constexpr string_view() noexcept = default;
constexpr string_view(const char *S, size_type Count)
: Data(S), Size(Count) {}
string_view(const char *S) : Data(S), Size(strlen(S)) {}
string_view(const std::string &S) : Data(S.data()), Size(S.size()) {}
constexpr const_iterator begin() const noexcept { return Data; }
constexpr const_iterator end() const noexcept { return Data + Size; }
constexpr const_pointer data() const noexcept { return Data; }
constexpr const_reference operator[](size_type idx) { return Data[idx]; }
constexpr size_type size() const noexcept { return Size; }
constexpr bool empty() const noexcept { return Size == 0; }
friend bool operator==(const string_view &LHS, const string_view &RHS) {
if (LHS.Size != RHS.Size)
return false;
if (LHS.Data == RHS.Data)
return true;
for (size_t I = 0; I != LHS.Size; ++I)
if (LHS.Data[I] != RHS.Data[I])
return false;
return true;
}
friend bool operator!=(const string_view &LHS, const string_view &RHS) {
return !(LHS == RHS);
}
private:
const char *Data = nullptr;
size_type Size = 0;
};
inline std::ostream &operator<<(std::ostream &OS, string_view S) {
return OS.write(S.data(), S.size());
}
} // end namespace __orc_rt
namespace std {
// Make string_view hashable.
// FIXME: This can be removed (along with the string_view class) when we move
// to C++17.
template <> struct hash<__orc_rt::string_view> {
size_t operator()(const __orc_rt::string_view &S) const {
std::string Tmp(S.data(), S.size());
return hash<std::string>()(Tmp);
}
};
} // namespace std
#endif // ORC_RT_ADT_H