thevar1able/ClickHouse
1
0
Fork 0
mirror of https://github.com/ClickHouse/ClickHouse.git synced 2024-11-24 16:42:05 +00:00
Code Issues Packages Projects Releases Wiki Activity

Improve ext::scope_guard.

Browse Source
This commit is contained in:
Vitaly Baranov 2020-03-05 17:42:02 +03:00
parent 2fd4439e5f
commit 598b373b35
1 changed files with 21 additions and 9 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

30
base/ext/scope_guard.h
View File

@ -12,20 +12,20 @@ class [[nodiscard]] basic_scope_guard
{ {
public: public:
constexpr basic_scope_guard() = default; constexpr basic_scope_guard() = default;
constexpr basic_scope_guard(basic_scope_guard && src) : function{std::exchange(src.function, {})} {} constexpr basic_scope_guard(basic_scope_guard && src) : function{src.release()} {}
constexpr basic_scope_guard & operator=(basic_scope_guard && src) constexpr basic_scope_guard & operator=(basic_scope_guard && src)
{ {
if (this != &src) if (this != &src)
{ {
invoke(); invoke();
function = std::exchange(src.function, {}); function = src.release();
} }
return *this; return *this;
} }
template <typename G, typename = std::enable_if_t<std::is_convertible_v<G, F>, void>> template <typename G, typename = std::enable_if_t<std::is_convertible_v<G, F>, void>>
constexpr basic_scope_guard(basic_scope_guard<G> && src) : function{std::exchange(src.function, {})} {} constexpr basic_scope_guard(basic_scope_guard<G> && src) : function{src.release()} {}
template <typename G, typename = std::enable_if_t<std::is_convertible_v<G, F>, void>> template <typename G, typename = std::enable_if_t<std::is_convertible_v<G, F>, void>>
constexpr basic_scope_guard & operator=(basic_scope_guard<G> && src) constexpr basic_scope_guard & operator=(basic_scope_guard<G> && src)
@ -33,7 +33,7 @@ public:
if (this != &src) if (this != &src)
{ {
invoke(); invoke();
function = std::exchange(src.function, {}); function = src.release();
} }
return *this; return *this;
} }
@ -46,14 +46,26 @@ public:
~basic_scope_guard() { invoke(); } ~basic_scope_guard() { invoke(); }
static constexpr bool is_nullable = std::is_constructible_v<bool, F>;
explicit operator bool() const explicit operator bool() const
{ {
if constexpr (std::is_constructible_v<bool, F>) if constexpr (is_nullable)
return static_cast<bool>(function); return static_cast<bool>(function);
return true; return true;
} }
void reset() { function = {}; } void reset()
{
invoke();
release();
}
F release()
{
static_assert(is_nullable);
return std::exchange(function, {});
}
template <typename G, typename = std::enable_if_t<std::is_convertible_v<G, F>, void>> template <typename G, typename = std::enable_if_t<std::is_convertible_v<G, F>, void>>
basic_scope_guard<F> & join(basic_scope_guard<G> && other) basic_scope_guard<F> & join(basic_scope_guard<G> && other)
@ -62,14 +74,14 @@ public:
{ {
if (function) if (function)
{ {
function = [x = std::make_shared<std::pair<F, G>>(std::move(function), std::exchange(other.function, {}))]() function = [x = std::make_shared<std::pair<F, G>>(std::move(function), other.release())]()
{ {
std::move(x->first)(); std::move(x->first)();
std::move(x->second)(); std::move(x->second)();
}; };
} }
else else
function = std::exchange(other.function, {}); function = other.release();
} }
return *this; return *this;
} }
@ -77,7 +89,7 @@ public:
private: private:
void invoke() void invoke()
{ {
if constexpr (std::is_constructible_v<bool, F>) if constexpr (is_nullable)
{ {
if (!function) if (!function)
return; return;