Merge pull request #138 from AlephAlpha/master

Make methods of `Config` const functions

Author: marshallpierce

src/lib.rs

@@ -161,7 +161,7 @@ pub struct Config {
 
 impl Config {
     /// Create a new `Config`.
-    pub fn new(char_set: CharacterSet, pad: bool) -> Config {
+    pub const fn new(char_set: CharacterSet, pad: bool) -> Config {
         Config {
             char_set,
             pad,
@@ -170,15 +170,15 @@ impl Config {
     }
 
     /// Sets whether to pad output with `=` characters.
-    pub fn pad(self, pad: bool) -> Config {
+    pub const fn pad(self, pad: bool) -> Config {
         Config { pad, ..self }
     }
 
     /// Sets whether to emit errors for nonzero trailing bits.
     ///
     /// This is useful when implementing
     /// [forgiving-base64 decode](https://infra.spec.whatwg.org/#forgiving-base64-decode).
-    pub fn decode_allow_trailing_bits(self, allow: bool) -> Config {
+    pub const fn decode_allow_trailing_bits(self, allow: bool) -> Config {
         Config {
             decode_allow_trailing_bits: allow,
             ..self
@@ -236,7 +236,7 @@ pub const IMAP_MUTF7: Config = Config {
 };
 
 /// BinHex character set
-pub const BINHEX : Config = Config {
+pub const BINHEX: Config = Config {
     char_set: CharacterSet::BinHex,
     pad: false,
     decode_allow_trailing_bits: false,