ipc_helpers: Add PushEnum() member function to ResponseBuilder

Allows pushing strongly-typed enum members without the need to always
cast them at the call sites.

Note that we *only* allow strongly-typed enums in this case. The reason
for this is that strongly typed enums have a guaranteed defined size, so
the size of the data being pushed is always deterministic. With regular
enums this can be a little more error-prone, so we disallow them.

This function simply uses the underlying type of the enum to determine
the size of the data. For example, if an enum is defined as:

enum class SomeEnum : u16 {
  SomeEntry
};

if PushEnum(SomeEnum::SomeEntry); is called, then it will push a
u16-size amount of data.
master
Lioncash 2018-07-20 14:49:13 +07:00
parent c1c9ab31e8
commit 0a0b3c4b9f
1 changed files with 19 additions and 0 deletions

@ -174,6 +174,25 @@ public:
template <typename First, typename... Other>
void Push(const First& first_value, const Other&... other_values);
/**
* Helper function for pushing strongly-typed enumeration values.
*
* @tparam Enum The enumeration type to be pushed
*
* @param value The value to push.
*
* @note The underlying size of the enumeration type is the size of the
* data that gets pushed. e.g. "enum class SomeEnum : u16" will
* push a u16-sized amount of data.
*/
template <typename Enum>
void PushEnum(Enum value) {
static_assert(std::is_enum_v<Enum>, "T must be an enum type within a PushEnum call.");
static_assert(!std::is_convertible_v<Enum, int>,
"enum type in PushEnum must be a strongly typed enum.");
Push(static_cast<std::underlying_type_t<Enum>>(value));
}
/**
* @brief Copies the content of the given trivially copyable class to the buffer as a normal
* param