vendor/error-chain-0.11.0/examples/size.rs

   1 #[macro_use]
   2 extern crate error_chain;
   3
   4 use std::mem::{size_of, size_of_val};
   5
   6 error_chain! {
   7     errors {
   8         AVariant
   9         Another
  10     }
  11 }
  12
  13 fn main() {
  14     println!("Memory usage in bytes");
  15     println!("---------------------");
  16     println!("Result<()>: {}", size_of::<Result<()>>());
  17     println!("  (): {}", size_of::<()>());
  18     println!("  Error: {}", size_of::<Error>());
  19     println!("    ErrorKind: {}", size_of::<ErrorKind>());
  20     let msg = ErrorKind::Msg("test".into());
  21     println!("      ErrorKind::Msg: {}", size_of_val(&msg));
  22     println!("        String: {}", size_of::<String>());
  23     println!("    State: {}", size_of::<error_chain::State>());
  24     #[cfg(feature = "backtrace")]
  25     {
  26         let state = error_chain::State {
  27             next_error: None,
  28             backtrace: None,
  29         };
  30         println!("      State.next_error: {}", size_of_val(&state.next_error));
  31         println!("      State.backtrace: {}", size_of_val(&state.backtrace));
  32     }
  33     #[cfg(not(feature = "backtrace"))]
  34     {
  35         let state = error_chain::State { next_error: None };
  36         println!("      State.next_error: {}", size_of_val(&state.next_error));
  37     }
  38 }