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Commit 4b351b61 authored by Benjamin Jaeger's avatar Benjamin Jaeger Committed by Facebook Github Bot
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Optional.h - make == operators constexprs 

Summary: This more closely matches std optional and allows folly Optional to be a drop in replacement.

Reviewed By: aary, yfeldblum

Differential Revision: D5775541

fbshipit-source-id: f754c006429fa3c5a866b6b5ffdfd8883ec2dd4f
parent d6217b2f
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Showing with 44 additions and 40 deletions
folly/Optional.h
View file @ 4b351b61
......@@ -104,7 +104,7 @@ class Optional {
!std::is_abstract<Value>::value,
"Optional may not be used with abstract types");
Optional() noexcept {}
FOLLY_CPP14_CONSTEXPR Optional() noexcept {}
Optional(const Optional& src) noexcept(
std::is_nothrow_copy_constructible<Value>::value) {
......@@ -121,20 +121,20 @@ class Optional {
}
}
/* implicit */ Optional(const None&) noexcept {}
FOLLY_CPP14_CONSTEXPR /* implicit */ Optional(const None&) noexcept {}
/* implicit */ Optional(Value&& newValue) noexcept(
FOLLY_CPP14_CONSTEXPR /* implicit */ Optional(Value&& newValue) noexcept(
std::is_nothrow_move_constructible<Value>::value) {
storage_.construct(std::move(newValue));
}
/* implicit */ Optional(const Value& newValue) noexcept(
FOLLY_CPP14_CONSTEXPR /* implicit */ Optional(const Value& newValue) noexcept(
std::is_nothrow_copy_constructible<Value>::value) {
storage_.construct(newValue);
}
template <typename... Args>
explicit Optional(in_place_t, Args&&... args) noexcept(
FOLLY_CPP14_CONSTEXPR explicit Optional(in_place_t, Args&&... args) noexcept(
std::is_nothrow_constructible<Value, Args...>::value) {
storage_.construct(std::forward<Args>(args)...);
}
......@@ -212,22 +212,22 @@ class Optional {
storage_.clear();
}
const Value& value() const & {
FOLLY_CPP14_CONSTEXPR const Value& value() const & {
require_value();
return *storage_.value_pointer();
}
Value& value() & {
FOLLY_CPP14_CONSTEXPR Value& value() & {
require_value();
return *storage_.value_pointer();
}
Value&& value() && {
FOLLY_CPP14_CONSTEXPR Value&& value() && {
require_value();
return std::move(*storage_.value_pointer());
}
const Value&& value() const && {
FOLLY_CPP14_CONSTEXPR const Value&& value() const && {
require_value();
return std::move(*storage_.value_pointer());
}
......@@ -240,37 +240,37 @@ class Optional {
}
Value* get_pointer() && = delete;
bool hasValue() const noexcept {
FOLLY_CPP14_CONSTEXPR bool hasValue() const noexcept {
return storage_.hasValue();
}
explicit operator bool() const noexcept {
FOLLY_CPP14_CONSTEXPR explicit operator bool() const noexcept {
return hasValue();
}
const Value& operator*() const & {
FOLLY_CPP14_CONSTEXPR const Value& operator*() const & {
return value();
}
Value& operator*() & {
FOLLY_CPP14_CONSTEXPR Value& operator*() & {
return value();
}
const Value&& operator*() const && {
FOLLY_CPP14_CONSTEXPR const Value&& operator*() const && {
return std::move(value());
}
Value&& operator*() && {
FOLLY_CPP14_CONSTEXPR Value&& operator*() && {
return std::move(value());
}
const Value* operator->() const {
FOLLY_CPP14_CONSTEXPR const Value* operator->() const {
return &value();
}
Value* operator->() {
FOLLY_CPP14_CONSTEXPR Value* operator->() {
return &value();
}
// Return a copy of the value if set, or a given default if not.
template <class U>
Value value_or(U&& dflt) const & {
FOLLY_CPP14_CONSTEXPR Value value_or(U&& dflt) const & {
if (storage_.hasValue()) {
return *storage_.value_pointer();
}
......@@ -279,7 +279,7 @@ class Optional {
}
template <class U>
Value value_or(U&& dflt) && {
FOLLY_CPP14_CONSTEXPR Value value_or(U&& dflt) && {
if (storage_.hasValue()) {
return std::move(*storage_.value_pointer());
}
......@@ -386,7 +386,7 @@ void swap(Optional<T>& a, Optional<T>& b) {
}
template <class T, class Opt = Optional<typename std::decay<T>::type>>
Opt make_optional(T&& v) {
constexpr Opt make_optional(T&& v) {
return Opt(std::forward<T>(v));
}
......@@ -394,27 +394,29 @@ Opt make_optional(T&& v) {
// Comparisons.
template <class U, class V>
bool operator==(const Optional<U>& a, const V& b) {
constexpr bool operator==(const Optional<U>& a, const V& b) {
return a.hasValue() && a.value() == b;
}
template <class U, class V>
bool operator!=(const Optional<U>& a, const V& b) {
constexpr bool operator!=(const Optional<U>& a, const V& b) {
return !(a == b);
}
template <class U, class V>
bool operator==(const U& a, const Optional<V>& b) {
constexpr bool operator==(const U& a, const Optional<V>& b) {
return b.hasValue() && b.value() == a;
}
template <class U, class V>
bool operator!=(const U& a, const Optional<V>& b) {
constexpr bool operator!=(const U& a, const Optional<V>& b) {
return !(a == b);
}
template <class U, class V>
bool operator==(const Optional<U>& a, const Optional<V>& b) {
FOLLY_CPP14_CONSTEXPR bool operator==(
const Optional<U>& a,
const Optional<V>& b) {
if (a.hasValue() != b.hasValue()) {
return false;
}
......@@ -425,12 +427,14 @@ bool operator==(const Optional<U>& a, const Optional<V>& b) {
}
template <class U, class V>
bool operator!=(const Optional<U>& a, const Optional<V>& b) {
constexpr bool operator!=(const Optional<U>& a, const Optional<V>& b) {
return !(a == b);
}
template <class U, class V>
bool operator<(const Optional<U>& a, const Optional<V>& b) {
FOLLY_CPP14_CONSTEXPR bool operator<(
const Optional<U>& a,
const Optional<V>& b) {
if (a.hasValue() != b.hasValue()) {
return a.hasValue() < b.hasValue();
}
......@@ -441,17 +445,17 @@ bool operator<(const Optional<U>& a, const Optional<V>& b) {
}
template <class U, class V>
bool operator>(const Optional<U>& a, const Optional<V>& b) {
constexpr bool operator>(const Optional<U>& a, const Optional<V>& b) {
return b < a;
}
template <class U, class V>
bool operator<=(const Optional<U>& a, const Optional<V>& b) {
constexpr bool operator<=(const Optional<U>& a, const Optional<V>& b) {
return !(b < a);
}
template <class U, class V>
bool operator>=(const Optional<U>& a, const Optional<V>& b) {
constexpr bool operator>=(const Optional<U>& a, const Optional<V>& b) {
return !(a < b);
}
......@@ -475,43 +479,43 @@ bool operator>(const V& other, const Optional<V>&) = delete;
// Comparisons with none
template <class V>
bool operator==(const Optional<V>& a, None) noexcept {
constexpr bool operator==(const Optional<V>& a, None) noexcept {
return !a.hasValue();
}
template <class V>
bool operator==(None, const Optional<V>& a) noexcept {
constexpr bool operator==(None, const Optional<V>& a) noexcept {
return !a.hasValue();
}
template <class V>
bool operator<(const Optional<V>&, None) noexcept {
constexpr bool operator<(const Optional<V>&, None) noexcept {
return false;
}
template <class V>
bool operator<(None, const Optional<V>& a) noexcept {
constexpr bool operator<(None, const Optional<V>& a) noexcept {
return a.hasValue();
}
template <class V>
bool operator>(const Optional<V>& a, None) noexcept {
constexpr bool operator>(const Optional<V>& a, None) noexcept {
return a.hasValue();
}
template <class V>
bool operator>(None, const Optional<V>&) noexcept {
constexpr bool operator>(None, const Optional<V>&) noexcept {
return false;
}
template <class V>
bool operator<=(None, const Optional<V>&) noexcept {
constexpr bool operator<=(None, const Optional<V>&) noexcept {
return true;
}
template <class V>
bool operator<=(const Optional<V>& a, None) noexcept {
constexpr bool operator<=(const Optional<V>& a, None) noexcept {
return !a.hasValue();
}
template <class V>
bool operator>=(const Optional<V>&, None) noexcept {
constexpr bool operator>=(const Optional<V>&, None) noexcept {
return true;
}
template <class V>
bool operator>=(None, const Optional<V>& a) noexcept {
constexpr bool operator>=(None, const Optional<V>& a) noexcept {
return !a.hasValue();
}
......
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