Dtypes and Promotion

Dtypes and Promotion

Headers: include/stratax/core/dtypes/Types.hpp, DTypeTraits.hpp, and Promotion.hpp; owning container result rules are in core/ArrayTraits.hpp.

Scalar aliases

Namespace	Names	C++ types
stratax::core	index_t, ssize_t	size_t, ptrdiff_t
stratax::dtype	bool_	bool
stratax::dtype	int8, int16, int32, int64	Corresponding fixed-width signed integers
stratax::dtype	uint8, uint16, uint32, uint64	Corresponding fixed-width unsigned integers
stratax::dtype	float32, float64, longdouble	float, double, long double
stratax::dtype	complex64, complex128, clongdouble	std::complex of those real types

There are no float128 or complex256 aliases. Floating-point names map to native C++ representations; long double precision is platform-dependent.

Metadata and result traits

stratax::core::DTypeTraits<T> removes cv/ref qualifiers and exposes type, kind, storage bits, precision digits, and name. Floating/complex types also have a promotion rank; complex metadata includes component_type. Storage bits may include padding. ComplexComponent and ComplexFromReal map between registered complex and real component dtypes.

promote_t<L, R> selects the result dtype through Promote specializations. Refer to the generated Promotion.hpp reference for category-specific rules; this is distinct from C++'s intermediate expression type. Allocating operations usually compute using original scalar types then convert the result. rebind_array_t<A, T> changes the dtype of an owning family; promote_array_t<L, R, T> retains matching families and chooses Tensor for mixed families. ArrayView has no supplied owning result specialization.

#include <stratax.h>
#include <type_traits>
 
using stratax::dtype::float64;
using stratax::core::index_t;
static_assert(std::is_same_v<float64, double>);
static_assert(std::is_same_v<stratax::core::promote_t<stratax::dtype::int16,
                                                  stratax::dtype::int32>,
                             stratax::dtype::int32>);
int main() {
    float64 value = 3.5;
    index_t count = 4;
    (void)value;
    (void)count;
}

All aliases and traits are compile-time constructs. They do not add checked casts, overflow detection, or runtime dtype dispatch. See DType and Array Concepts.