On Sunday, 24 November 2013 at 14:24:09 UTC, ilya-stromberg wrote:
On Sunday, 24 November 2013 at 14:17:50 UTC, Dicebot wrote:
Not exactly. It is all about "if" condition. AFAIK, D defines
that condition `if(X)` get re-written to `if(cast(bool)X)`
before semantic pass. So it is kind of implicit explicit
conversion :)
Not exactly.
Code:
bool b = f;
DMD output:
Error: cannot implicitly convert expression (f) of type Foo to
bool
But code:
bool b = !f;
compiles.
Because '!' operator provides boolean context. It is written in
the spec, although not explicitly. By the way, the same happens
with objects with pretty many types (except structs which do not
provide necessary operator overloads), so classes are not
exceptional here.
UnaryExpression:
& UnaryExpression
++ UnaryExpression
-- UnaryExpression
* UnaryExpression
- UnaryExpression
+ UnaryExpression
! UnaryExpression
ComplementExpression
( Type ) . Identifier
( Type ) . TemplateInstance
DeleteExpression
CastExpression
PowExpression
