Method lookup

The region check is a final pass that runs over the AST after we have inferred the type constraints but before we have actually finalized the types. Its purpose is to embed a variety of region constraints. Inserting these constraints as a separate pass is good because (1) it localizes the code that has to do with region inference and (2) often we cannot know what constraints are needed until the basic types have been inferred.

Fields that are part of a FnCtxt which are inherited by closures defined within the function. For example:

Executes an autoderef loop for the type t. At each step, invokes should_stop to decide whether to terminate the loop. Returns the final type and number of derefs that it performed.

Checks whether a type can be created without an instance of itself. This is similar but different from the question of whether a type can be represented. For example, the following type:

Checks whether a type can be represented in memory. In particular, it identifies types that contain themselves without indirection through a pointer, which would mean their size is unbounded. This is different from the question of whether a type can be instantiated. See the definition of check_instantiable.