Rule 5.1

An integer-written literal must take the integer type the position around it declares. An unannotated function-local let or const initialized by such a literal takes i32 or u32 when declared uses require that one type for the local: direct calls to declared, nongeneric functions, constructor and instance or static method arguments, and explicitly typed initialization or simple assignment. A simple assignment can take the type of its destination or of a right-hand side that declares its type independently of the local. Resolve the local, callee and receiver by their declarations, including through nested scopes and inherited members; an override supplies its own signature. A concrete member parameter independent of generic arguments can establish a demand; an unresolved generic parameter or circular inference cannot. Conflicting concrete scalar types must be refused with an annotation or cast remedy. Where no integer type is established, the literal must be an f32.