reserve

gistfile1.rs

fn reserve(&ss: str, nn: uint) unsafe {
   // start with an existing string

   str::char_len(ss); std::io::println("+++A+++");

   // make a vector
   let vv: [u8] = unsafe::reinterpret_cast(ss);
   
   str::char_len(ss); std::io::println("+++B+++");

   // expand it to size + \0
   vec::reserve(vv, nn+1u);

   // FIXME:
   // fails here sometimes on assertion in byte_len called by char_len
   str::char_len(ss); std::io::println("+++C+++");

   // forget the vector
   unsafe::leak(vv);

   str::char_len(ss); std::io::println("+++D+++");
}

/* EXAMPLE ERROR:
   ...
   +++A+++
   +++B+++
   rust: upcall fail 'Assertion vlen > 0 failed', src/libcore/str.rs:133
   rust: domain main @0x16d6510 root task failed
   rust: fatal, 'live_allocs < 1' failed, ./src/rt/memory_region.cpp:54 
   Aborted

*/