Are asserts enough to make method @trusted or is something like
throw exception or return error code necessary? How it work in
phobos?
Example:
```d
struct Slice(T){
private T[] data;
this(T[] data){
this.data = data;
}
inout(T)[] opSlice()inout scope return pure nothrow @safe
@nogc{
return data;
}
inout(T)[] opSlice(size_t b, size_t e)inout scope return pure
nothrow @safe @nogc{
return data[b .. e];
}
/*
Remove subset `slice` from `this.data`
`slice` is subset of `this.data`.
*/
void erase1(scope const(T)[] slice)scope pure nothrow
@trusted @nogc{
assert(data.ptr <= slice.ptr);
assert((slice.ptr + slice.length) <= (data.ptr +
data.length));
//...
}
// ditto
bool erase2(scope const(T)[] slice)scope pure nothrow
@trusted @nogc{
if(data.ptr > slice.ptr)
return false;
if((slice.ptr + slice.length) > (data.ptr + data.length))
return false;
//...
assert(0, "TODO impl");
}
}
void main()@safe{
scope slice = Slice!int([1, 2, 3, 4]);
scope slice2 = Slice!int([1, 2, 3, 4]);
slice.erase2(slice2[1 .. 2]); //return false
slice.erase1(slice2[1 .. 2]); //assert error in debug
}
```
