maybe monad

This is the C++ template metaprogramming equivalent of Haskell's Maybe monad. The purpose of this monad is to provide basic error handling for pure code. Note that metamonad offers a higher level error handling monad, the exception monad.

Monadic values comprise nothing and just<T>, where T is a nullary metafunction. just evaluates its argument. nothing represents error, just represents normal result.

General information

• header: <mpllibs/metamonad/maybe.hpp>
• tag of monad: maybe_tag<T> where T is the tag of the value wrapped by just.
• return's logic: pass the argument to just
• bind's logic: when the first argument is nothing, bind returns it as it is. When it is just, bind passes the wrapped value to the continuation, the last argument of bind.
• fail's logic: return nothing

Copyright Abel Sinkovics (abel at elte dot hu) 2011. Distributed under the Boost Software License, Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt

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