On Friday, 14 April 2023 at 14:10:41 UTC, Leonardo wrote:
Thanks. But this works only to one function per time. Is there
any way to do this to an imported library at all? something
like `@trusted import library`
No, there isn't. C is an unsafe language, so if you want to call
C from `@safe` code, you have to do the work to make sure that
each individual call is `@safe`.
If you are calling the same C function many times from `@safe`
code, you can write a `@trusted` D wrapper function to avoid
repeating the safety checks at every call site. For example,
here's a `@trusted` wrapper for the standard C library function
`puts`:
```d
import core.stdc.stdio: puts;
import std.exception: enforce;
@trusted
void safePuts(const(char)[] s)
{
// To safely call puts, we must pass it a valid C string
// To be a valid C string, s must be non-empty and
NUL-terminated
enforce(s.length > 0, "An empty string is not a C string");
enforce(s[$-1] == '\0', "A C string must be NUL-terminated");
// If the checks above have passed, this call is safe
puts(&s[0]);
}
```
