mirror of
https://github.com/carbon-language/carbon-lang.git
synced 2026-10-04 22:02:52 +01:00
f63169608e
Proposal to support a limited set of implicit conversions. This would generally permit only implicit conversions that are lossless and semantics-preserving. In particular, this proposal allows: - Conversion from an integer type to a wider integer type of the same signedness, and from an unsigned integer type to a wider signed integer type. - Conversion from an integer type to a floating-point type that has enough mantissa bits to exactly represent all integers in the source type. - Conversion from integer literals to integer and floating-point types that can represent them. - Conversion from floating-point literals to floating-point types that can represent them. - Conversions required for generics: conversions of values between facet types, and conversions of types between type-of-types, as described in the generics proposals. - Conversions required for inheritance: derived-to-base conversions for class pointers and class values. Other conversions, such as lossy conversions between arithmetic types and conversions between bool and other types are not supported. Co-authored-by: josh11b <josh11b@users.noreply.github.com> Co-authored-by: Chandler Carruth <chandlerc@gmail.com> Co-authored-by: Geoff Romer <gromer@google.com>
990 B
990 B
Expressions
Table of contents
Overview
Expressions are the portions of Carbon syntax that produce values. Because types in Carbon are values, this includes anywhere that a type is specified.
fn Foo(a: i32*) -> i32 {
return *a;
}
Here, the parameter type i32*, the return type i32, and the operand *a of
the return statement are all expressions.
Implicit conversions
When an expression appears in a context in which an expression of a specific type is expected, implicit conversions are applied to convert the expression to the target type.
fn Bar(n: i32);
fn Baz(n: i64) {
// OK, same as Bar(n as i32)
Bar(n);
}