tree 27100bce2109092e7b6287123e7cb026610adde9
parent 105e3d0d193906ace416cc994664dbce23dbe1db
author David Calavera <david.calavera@gmail.com> 1449771257 -0500
committer Steve Francia <steve.francia@gmail.com> 1450970201 -0500

Add FlagValue interface to support other flag systems.

Using an interface allows people to use their favourite flag system
with viper without being restricted to the semantics of pflag or the
standard library.

This change introduce two new functions `BindFlagValues` and
`BindFlagValue` that behave like `BindFlags` and `BindFlag` but using
the new interface as values.

This change also introduces two internal structures to transform
`*pflag.FlagSet` and `*pflag.Flag` into the new interface. This way,
viper keeps working as expected for people that are currently using the
pflag package without breaking backwards compatibility.

Signed-off-by: David Calavera <david.calavera@gmail.com>