Desugaring Bindings

All the let expressions left are now bindings. We desugar them all into binding declarations and assignments:

• By-value bindings:

  #![allow(unused)]
  fn main() {
  let x = $place;
  
  // becomes
  let x: $ty;
  x = &$place;
  }

• By-ref bindings:

  #![allow(unused)]
  fn main() {
  let ref x = $place;
  
  // becomes
  let x: $ty;
  x = &$place;
  }

• By-ref-mut bindings:

  #![allow(unused)]
  fn main() {
  let ref mut x = $place;
  
  // becomes
  let x: $ty;
  x = &mut $place;
  }

• Place aliases:

  For place aliases, the RHS is already a side-effect-free place expression. We can therefore simply substitute $place for p syntactically. For example:

  #![allow(unused)]
  fn main() {
  let place p = x.field;
  something(&p);
  something_else(p);
  
  // becomes:
  something(&x.field);
  something_else(x.field);
  }

At the end of this step, all the bindings are declared uninitialized (let x;/let mut x;).

Backlinks

• Closure To Struct Desugaring
• Place Aliases