Module ty 

Util methods for rustc_middle::ty

Modules

type_certainty 🔒

A heuristic to tell whether an expression’s type can be determined purely from its subexpressions, and the arguments and locals they use. Put another way, expr_type_is_certain tries to tell whether an expression’s type can be determined without appeal to the surrounding context.

Structs

AdtVariantInfo

InteriorMut

Helper to check if given type has inner mutability such as std::cell::Cell or std::cell::RefCell.

Enums

EnumValue

ExprFnSig

A signature for a function like type.

Functions

adjust_derefs_manually_drop

Checks if the adjustments contain a mutable dereference of a ManuallyDrop<_>.

adt_and_variant_of_res

Gets the struct or enum variant from the given Res

all_predicates_of

Gets an iterator over all predicates which apply to the given item.

approx_ty_size

Comes up with an “at least” guesstimate for the type’s size, not taking into account the layout of type parameters.

assert_generic_args_match 🔒

Asserts that the given arguments match the generic parameters of the given item.

can_partially_move_ty

Checks whether a type can be partially moved.

contains_adt_constructor

Walks into ty and returns true if any inner type is an instance of the given adt constructor.

contains_ty_adt_constructor_opaque

Walks into ty and returns true if any inner type is an instance of the given type, or adt constructor of the same type.

deref_chain

Returns the deref chain of a type, starting with the type itself.

expr_sig

If the expression is function like, get the signature for it.

expr_type_is_certain

for_each_top_level_late_bound_region

get_adt_inherent_method

Checks if a Ty<’_> has some inherent method Symbol.

get_discriminant_value

Gets the value of the given variant.

get_field_by_name

Gets the type of a field by name.

get_field_idx_by_name

get_iterator_item_ty

Resolves <T as Iterator>::Item for T Do not invoke without first verifying that the type implements Iterator

get_type_diagnostic_name

Get the diagnostic name of a type, e.g. sym::HashMap. To check if a type implements a trait marked with a diagnostic item use implements_trait.

has_debug_impl

This checks whether a given type is known to implement Debug.

has_drop

Checks whether this type implements Drop.

has_iter_method

If ty is known to have a iter or iter_mut method, returns a symbol representing the type.

has_non_owning_mutable_access

Check if a Ty<’_> of Iterator contains any mutable access to non-owning types by checking if it contains fields of mutable references or pointers, or references/pointers to non-Freeze types, or PhantomData types containing any of the previous. This can be used to check whether skipping iterating over an iterator will change its behavior.

implements_trait

Checks whether a type implements a trait. The function returns false in case the type contains an inference variable.

implements_trait_with_env

Same as implements_trait but allows using a ParamEnv different from the lint context.

implements_trait_with_env_from_iter

Same as implements_trait_from_env but takes the arguments as an iterator.

is_c_void

Check if the given type is either core::ffi::c_void, std::os::raw::c_void, or one of the platform specific libc::<platform>::c_void types in libc.

is_copy

Checks if the given type implements copy.

is_isize_or_usize

Return true if the passed typ is isize or usize.

is_manually_drop

Checks if the type is core::mem::ManuallyDrop<_>

is_must_use_ty

is_never_like

Returns whether ty is never-like; i.e., ! (never) or an enum with zero variants.

is_non_aggregate_primitive_type

Returns true if the given type is a non aggregate primitive (a bool or char, any integer or floating-point number type).

is_recursively_primitive_type

Returns true if the given type is a primitive (a bool or char, any integer or floating-point number type, a str, or an array, slice, or tuple of those types).

is_slice_like

Check if ty is slice-like, i.e., &[T], [T; N], or Vec<T>.

is_type_diagnostic_item

Checks if the type is equal to a diagnostic item. To check if a type implements a trait marked with a diagnostic item use implements_trait.

is_type_lang_item

Checks if the type is equal to a lang item.

is_type_ref_to_diagnostic_item

Checks if the type is a reference equals to a diagnostic item

is_uninit_value_valid_for_ty

Checks if a given type looks safe to be uninitialized.

is_uninit_value_valid_for_ty_fallback 🔒

A fallback for polymorphic types, which are not supported by check_validity_requirement.

is_unsafe_fn

Returns true if ty denotes an unsafe fn.

make_normalized_projection

Normalizes the named associated type in the given impl or trait impl.

make_normalized_projection_with_regions

make_projection

Makes the projection type for the named associated type in the given impl or trait impl.

needs_ordered_drop

Checks if the drop order for a type matters.

normalize_with_regions

option_arg_ty

Check if ty is an Option and return its argument type if it is.

peel_and_count_ty_refs

Peels off all references on the type. Returns the underlying type, the number of references removed, and, if there were any such references, whether the pointer is ultimately mutable or not.

read_explicit_enum_value

Attempts to read the given constant as though it were an enum value.

same_type_modulo_regions

Checks whether a and b are same types having same Const generic args, but ignores lifetimes.

should_call_clone_as_function

Returns true if ty is a type on which calling Clone through a function instead of as a method, such as Arc::clone() is considered idiomatic.

sig_for_projection 🔒

sig_from_bounds 🔒

ty_from_hir_ty

Lower a hir::Ty to a rustc_middle::ty::Ty.

ty_sig

If the type is function like, get the signature for it.