0.4.1

• Fix compile failure with non-cargo build systems.

0.4.0

• Add support for version-based code generation. The following conditions are available:

  use const_fn::const_fn;
  
  // function is `const` on specified version and later compiler (including beta and nightly)
  #[const_fn("1.36")]
  pub const fn version() {
      /* ... */
  }
  
  // function is `const` on nightly compiler (including dev build)
  #[const_fn(nightly)]
  pub const fn nightly() {
      /* ... */
  }
  
  // function is `const` if `cfg(...)` is true
  #[const_fn(cfg(...))]
  pub const fn cfg() {
      /* ... */
  }
  
  // function is `const` if `cfg(feature = "...")` is true
  #[const_fn(feature = "...")]
  pub const fn feature() {
      /* ... */
  }

• Improve compile time by removing proc-macro related dependencies (#18, #20).