tannic::transformation::Composition Struct Reference

Transformation composition (Known as Matrix Multiplication) operation. More...

#include <transformations.hpp>

Public Member Functions
void	forward (Tensor const &outer, Tensor const &inner, Tensor &result) const

Static Public Member Functions
static constexpr type	promote (type inner, type outer)
	Promotes two operand types to a common type for composition operations.
static constexpr Shape	transform (Shape const &first, Shape const &second)
	Computes transformed output shape for composition.

Public Attributes
double	scale = 1.0

Static Public Attributes
static constexpr auto	promotions
	Type promotion rules table.

Detailed Description

Transformation composition (Known as Matrix Multiplication) operation.

Implements tensor composition with:

• Automatic type promotion
• Shape broadcasting for batch dimensions
• Support for vectors, matrices, and higher-rank tensors

Member Function Documentation

forward()

void tannic::transformation::Composition::forward	(	Tensor const &	outer,
		Tensor const &	inner,
		Tensor &	result
	)		const

promote()

static constexpr type tannic::transformation::Composition::promote ( type  inner, type  outer  )

inlinestaticconstexpr

Promotes two operand types to a common type for composition operations.

Parameters

inner	Type of the inner (right) operand
outer	Type of the outer (left) operand

Returns

Promoted type according to the composition rules

Exceptions

assertion

error if the type combination is unsupported

This promotion system:

1. Uses a precomputed promotion table for all valid type combinations
2. Ensures safe arithmetic by:
   • Promoting integers to avoid overflow (e.g., int8 → int32)
   • Promoting mixed integer/float to float
   • Preserving higher precision when types differ
3. Explicitly rejects invalid combinations via assertion

Example promotions:

promote(int8, int32) → int32  // Integer widening
promote(int32, float32) → float32  // Mixed to float
promote(float32, float64) → float64  // Precision preservation

transform()

static constexpr Shape tannic::transformation::Composition::transform ( Shape const &  first, Shape const &  second  )

inlinestaticconstexpr

Computes transformed output shape for composition.

Parameters

first	First operand shape
second	Second operand shape

Returns

Broadcasted output shape

Exceptions

assertion

error if shapes are incompatible

Handles multiple cases:

1. Vector-vector: (n) × (n) → scalar (empty shape)
2. Matrix-vector: (m,n) × (n) → (m)
3. Vector-matrix: (n) × (n,k) → (k)
4. Matrix-matrix: (m,n) × (n,k) → (m,k)
5. Batched operations: (...,m,n) × (...,n,k) → (...,m,k)

Member Data Documentation

promotions

constexpr auto tannic::transformation::Composition::promotions

staticconstexpr

Type promotion rules table.

Defines promotion rules for all type combinations:

• Integer operations promote to avoid overflow
• Mixed integer/float promotes to float
• Operations preserve highest precision

scale

double tannic::transformation::Composition::scale = 1.0

---

The documentation for this struct was generated from the following file:

• include/tannic/transformations.hpp