Mojo function

struct_field_type_by_name

struct_field_type_by_name[StructT: AnyType, name: StringLiteral[value]]() -> ReflectedType[#kgen.struct_field_type_by_name<:trait<_std::_builtin::_anytype::_AnyType> StructT, #kgen.param.decl.ref<"name.value"> : !kgen.string>]`

Returns the type of the field with the given name in struct StructT.

This function provides compile-time lookup of a struct field's type by name. It produces a compile error if the field name does not exist in the struct.

The returned ReflectedType wrapper contains the field type as its T parameter, which can be used as a type in declarations.

Note: StructT must be a concrete type, not a generic type parameter. See the module documentation for details on this limitation.

Example:

struct Point:
    var x: Int
    var y: Float64

fn example():
    # Get the type of field "x"
    comptime x_type = struct_field_type_by_name[Point, "x"]()
    # x_type.T is Int
    var value: x_type.T = 42

Parameters:

StructT (AnyType): A concrete struct type to introspect.
name (StringLiteral): The name of the field to look up.

Returns:

ReflectedType: A ReflectedType wrapper containing the field's type.