Sturcts with constructor (dmd1.x)

[Nrgyzer]

Hello everyone,

I currently try to create a structure with a construtor, but I always get the 
following messages:

Error: Foo.this constructors are only for class definitions
Error: constructor lisim.lsResult.lsResult.this special member functions not 
allowed for structs

By compiling the follwing code:

struct Foo {
    int len;
    bool len_done;
    const char* str;
    int length()
    {   if (!len_done)
        {   len = strlen(str);
            len_done = true;
        }
        return len;
    }
    this(char* str) { this.str = str; }
}
const Foo f = Foo("hello");
bar(f.length);

I found that source on 
http://www.digitalmars.com/d/2.0/const-faq.html#logical-const. I know that this 
source is for d2 and not for d1 but does d1 support similar operations (or is 
there no support for struct-constructors)?

Thanks in advance :)