traits

Fully qualified name: carb::variant::traits

Defined in carb/variant/VariantUtils.h

struct traits

A structure containing functions for performing the prescribed actions on a VariantData. The functions handle the default behavior if the v-table or v-table function are nullptr.

Public Static Functions

static void swap(VariantData &lhs, VariantData &rhs) noexcept

Swaps two VariantData members.

Note

VariantData is treated as a trivial type and no v-table functions are required to perform this.

Parameters:

• lhs – The left-hand VariantData.

• rhs – The right-hand VariantData.

static void destruct(VariantData &self) noexcept

Destructs a VariantData.

See also

VTable::Destructor

Note

The default behavior (if !self.vtable->Destructor) treats self as trivially destructible.

Parameters:

self – The VariantData to destruct.

static VariantData copy(const VariantData &self) noexcept

Copies a VariantData.

See also

VTable::Copy

Note

The default behavior (if !self.vtable->Copy) treats self as trivially copyable.

Parameters:

self – The VariantData to copy.

Returns:

A VariantData that represents a copy of self. The v-table of the return value must be the same as self.vtable. When finished with the return value, it must be destroyed via destruct().

static bool equals(

const VariantData &self,

const VariantData &other,

) noexcept

Tests two VariantData instances for equality.

See also

VTable::Equals

Note

The default behavior (if !self.vtable->Equals) treats self and other as trivially comparable (i.e. bitwise compare via std::memcmp).

Parameters:

• self – The VariantData to compare. This parameter provides the v-table for the comparison.

• other – The other VariantData to compare.

Returns:

true if self and other are equal; false otherwise.

static omni::string toString(const VariantData &self) noexcept

Renders a VariantData as a string for debugging purposes.

See also

VTable::ToString

Note

The default behavior (if !self.vtable->ToString) produces "<vtable>:<data>".

Parameters:

self – The VariantData to render as a string.

Returns:

A string representing self for debugging purposes.

static bool convertTo(

const VariantData &self,

const VTable *newType,

VariantData &out,

) noexcept

Attempts to convert a VariantData to a different type.

If newType is the same as self.vtable, then traits::copy() is invoked instead.

See also

VTable::ConvertTo

Note

The default behavior (if !self.vtable->ConvertTo) merely returns false.

Parameters:

• self – The VariantData to convert. This parameter provides the v-table for the comparison.

• newType – The v-table representing the type to convert to.

• out – The VariantData to write the result to. Only valid if true is returned.

Returns:

true if and only if out contains a valid converted representation of self; false otherwise.

static size_t hash(const VariantData &self) noexcept

Computes a hash of a VariantData.

See also

VTable::Hash

Note

The default behavior (if !self.vtable->Hash) produces size_t(self.data).

Parameters:

self – The VariantData to hash.

Returns:

A hash value representing self.

static bool convertFrom(

const VTable *desired,

VariantData &out,

const VariantData &from,

) noexcept

Attempts to convert a VariantData to a different type.

If desired is the same as from.vtable, then traits::copy() is invoked instead.

See also

VTable::ConvertFrom

Note

The default behavior (if !from.vtable->ConvertFrom) merely returns false.

Parameters:

• desired – The v-table representing the type to convert to.

• out – The VariantData to write the result to. Only valid if true is returned.

• from – The VariantData to convert from.

Returns:

true if and only if out contains a valid converted representation of from; false otherwise.