class PointerUnion

Declaration

template <typename... PTs>
class PointerUnion { /* full declaration omitted */ };

Description

A discriminated union of two or more pointer types, with the discriminator in the low bit of the pointer. This implementation is extremely efficient in space due to leveraging the low bits of the pointer, while exposing a natural and type-safe API. Common use patterns would be something like this: PointerUnion <int *, float*> P; P = (int*)0; printf("%d %d", P.is <int *>(), P.is <float *>()); // prints "1 0" X = P.get <int *>(); // ok. Y = P.get <float *>(); // runtime assertion failure. Z = P.get <double *>(); // compile time failure. P = (float*)0; Y = P.get <float *>(); // ok. X = P.get <int *>(); // runtime assertion failure.

Declared at: llvm/include/llvm/ADT/PointerUnion.h:156

Templates

PTs

Method Overview

Methods

PointerUnion<PTs...>()

Declared at: llvm/include/llvm/ADT/PointerUnion.h:172

PointerUnion<PTs...>(std::nullptr_t)

Declared at: llvm/include/llvm/ADT/PointerUnion.h:174

Parameters

std::nullptr_t 

template <typename T>
T dyn_cast() const

Description

Returns the current pointer if it is of the specified pointer type, otherwises returns null.

Declared at: llvm/include/llvm/ADT/PointerUnion.h:201

Templates

T

template <typename T>
T get() const

Description

Returns the value of the specified pointer type. If the specified pointer type is incorrect, assert.

Declared at: llvm/include/llvm/ADT/PointerUnion.h:194

Templates

T

const llvm::PointerUnion::First* getAddrOfPtr1()
    const

Description

If the union is set to the first pointer type get an address pointing to it.

Declared at: llvm/include/llvm/ADT/PointerUnion.h:209

llvm::PointerUnion::First* getAddrOfPtr1()

Description

If the union is set to the first pointer type get an address pointing to it.

Declared at: llvm/include/llvm/ADT/PointerUnion.h:215

static inline PointerUnion<PTs...>
getFromOpaqueValue(void* VP)

Declared at: llvm/include/llvm/ADT/PointerUnion.h:235

Parameters

void* VP

void* getOpaqueValue() const

Declared at: llvm/include/llvm/ADT/PointerUnion.h:234

template <typename T>
int is() const

Description

Test if the Union currently holds the type matching T.

Declared at: llvm/include/llvm/ADT/PointerUnion.h:184

Templates

T

bool isNull() const

Description

Test if the pointer held in the union is null, regardless of which type it is.

Declared at: llvm/include/llvm/ADT/PointerUnion.h:179

bool operator bool() const

Declared at: llvm/include/llvm/ADT/PointerUnion.h:181