On Thursday, 27 May 2021 at 03:40:02 UTC, Виталий Фадеев wrote:
On Wednesday, 26 May 2021 at 16:35:36 UTC, Ali Çehreli wrote:
On 5/25/21 9:00 PM, Виталий Фадеев wrote:
> immutable(char)* toStringz( ref string s )
> {
> if ( s.capacity <= s.length )
> s.reserve( s.length + 1 );
>
> char* cptr = cast( char* ) s.ptr; // C ptr
> char* zptr = cptr + s.length; // zero ptr
> *zptr = '\0';
That's undefined behavior because that location does not
belong to the string. Here is an example that defeats the
proposed toStringz:
void main()
{
string s;
s = "D string";
auto c_string = toStringz( s );
auto other = s;
other ~= 'X'; // <-- Seemingly unrelated operation
// ...
}
puts accesses that unrelated 'X' and more bytes after that:
C string: D stringX1^
Ali
Yes. True.
reserve/capacity - not for all cases.
Zero terminator not keeped after concatenate source string with
other string.
auto dString = "D string" ~ 2.to!string;
auto cString = dString.toStringz();
dString = dString ~ "new tail";
// cString[ $-1 ] != '\'0';
