1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
|
//===-- Optional.h - Simple variant for passing optional values ---*- C++ -*-=//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file provides Optional, a template class modeled in the spirit of
// OCaml's 'opt' variant. The idea is to strongly type whether or not
// a value can be optional.
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_ADT_OPTIONAL_H
#define LLVM_ADT_OPTIONAL_H
#include "llvm/Support/Compiler.h"
#include <cassert>
#if LLVM_HAS_RVALUE_REFERENCES
#include <utility>
#endif
namespace llvm {
template<typename T>
class Optional {
T x;
bool hasVal;
public:
explicit Optional() : x(), hasVal(false) {}
Optional(const T &y) : x(y), hasVal(true) {}
#if LLVM_HAS_RVALUE_REFERENCES
Optional(T &&y) : x(std::forward<T>(y)), hasVal(true) {}
#endif
static inline Optional create(const T* y) {
return y ? Optional(*y) : Optional();
}
Optional &operator=(const T &y) {
x = y;
hasVal = true;
return *this;
}
const T* getPointer() const { assert(hasVal); return &x; }
const T& getValue() const LLVM_LVALUE_FUNCTION { assert(hasVal); return x; }
operator bool() const { return hasVal; }
bool hasValue() const { return hasVal; }
const T* operator->() const { return getPointer(); }
const T& operator*() const LLVM_LVALUE_FUNCTION { assert(hasVal); return x; }
#if LLVM_HAS_RVALUE_REFERENCE_THIS
T&& getValue() && { assert(hasVal); return std::move(x); }
T&& operator*() && { assert(hasVal); return std::move(x); }
#endif
};
template<typename T> struct simplify_type;
template <typename T>
struct simplify_type<const Optional<T> > {
typedef const T* SimpleType;
static SimpleType getSimplifiedValue(const Optional<T> &Val) {
return Val.getPointer();
}
};
template <typename T>
struct simplify_type<Optional<T> >
: public simplify_type<const Optional<T> > {};
/// \brief Poison comparison between two \c Optional objects. Clients needs to
/// explicitly compare the underlying values and account for empty \c Optional
/// objects.
///
/// This routine will never be defined. It returns \c void to help diagnose
/// errors at compile time.
template<typename T, typename U>
void operator==(const Optional<T> &X, const Optional<U> &Y);
/// \brief Poison comparison between two \c Optional objects. Clients needs to
/// explicitly compare the underlying values and account for empty \c Optional
/// objects.
///
/// This routine will never be defined. It returns \c void to help diagnose
/// errors at compile time.
template<typename T, typename U>
void operator!=(const Optional<T> &X, const Optional<U> &Y);
/// \brief Poison comparison between two \c Optional objects. Clients needs to
/// explicitly compare the underlying values and account for empty \c Optional
/// objects.
///
/// This routine will never be defined. It returns \c void to help diagnose
/// errors at compile time.
template<typename T, typename U>
void operator<(const Optional<T> &X, const Optional<U> &Y);
/// \brief Poison comparison between two \c Optional objects. Clients needs to
/// explicitly compare the underlying values and account for empty \c Optional
/// objects.
///
/// This routine will never be defined. It returns \c void to help diagnose
/// errors at compile time.
template<typename T, typename U>
void operator<=(const Optional<T> &X, const Optional<U> &Y);
/// \brief Poison comparison between two \c Optional objects. Clients needs to
/// explicitly compare the underlying values and account for empty \c Optional
/// objects.
///
/// This routine will never be defined. It returns \c void to help diagnose
/// errors at compile time.
template<typename T, typename U>
void operator>=(const Optional<T> &X, const Optional<U> &Y);
/// \brief Poison comparison between two \c Optional objects. Clients needs to
/// explicitly compare the underlying values and account for empty \c Optional
/// objects.
///
/// This routine will never be defined. It returns \c void to help diagnose
/// errors at compile time.
template<typename T, typename U>
void operator>(const Optional<T> &X, const Optional<U> &Y);
} // end llvm namespace
#endif
|
