[linalg.tags.order]

# 29 Numerics library [[numerics]](./#numerics)

## 29.9 Basic linear algebra algorithms [[linalg]](linalg#tags.order)

### 29.9.5 Tag classes [[linalg.tags]](linalg.tags#order)

#### 29.9.5.1 Storage order tags [linalg.tags.order]

[1](#1)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/numerics.tex#L11933)

The storage order tags describe
the order of elements in an mdspan withlayout_blas_packed ([[linalg.layout.packed]](linalg.layout.packed "29.9.6 Layouts for packed matrix types")) layout[.](#1.sentence-1)

[ð](#itemdecl:1)

`struct [column_major_t](#lib:column_major_t "29.9.5.1 Storage order tags [linalg.tags.order]") {
  explicit column_major_t() = default;
};
inline constexpr column_major_t [column_major](#lib:column_major "29.9.5.1 Storage order tags [linalg.tags.order]"){};

struct [row_major_t](#lib:row_major_t "29.9.5.1 Storage order tags [linalg.tags.order]") {
  explicit row_major_t() = default;
};
inline constexpr row_major_t [row_major](#lib:row_major "29.9.5.1 Storage order tags [linalg.tags.order]"){};
`

[2](#2)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/numerics.tex#L11950)

column_major_t indicates a column-major order,
and row_major_t indicates a row-major order[.](#2.sentence-1)
