# Module rustc_hir_analysis::variance::constraints

source · ## Expand description

Code to gather up constraints. Constraint construction and representation

The second pass over the AST determines the set of constraints. We walk the set of items and, for each member, generate new constraints.

## Structs

- Declares that the variable
`decl_id`

appears in a location with variance`variance`

. - To build constraints, we visit one item (type, trait) at a time and look at its contents. So e.g., if we have