Do not use fold expressions for mp_find and mp_find_if

Author: pdimov

include/boost/mp11/algorithm.hpp

@@ -719,37 +719,7 @@ namespace detail
 
 template<class L, class V> struct mp_find_impl;
 
-#if BOOST_MP11_CLANG && defined( BOOST_MP11_HAS_FOLD_EXPRESSIONS )
-
-struct mp_index_holder
-{
-    std::size_t i_;
-    bool f_;
-};
-
-constexpr inline mp_index_holder operator+( mp_index_holder const & v, bool f )
-{
-    if( v.f_ )
-    {
-        return v;
-    }
-    else if( f )
-    {
-        return { v.i_, true };
-    }
-    else
-    {
-        return { v.i_ + 1, false };
-    }
-}
-
-template<template<class...> class L, class... T, class V> struct mp_find_impl<L<T...>, V>
-{
-    static constexpr mp_index_holder _v{ 0, false };
-    using type = mp_size_t< (_v + ... + std::is_same<T, V>::value).i_ >;
-};
-
-#elif !defined( BOOST_MP11_NO_CONSTEXPR )
+#if !defined( BOOST_MP11_NO_CONSTEXPR )
 
 template<template<class...> class L, class V> struct mp_find_impl<L<>, V>
 {
@@ -828,15 +798,7 @@ namespace detail
 
 template<class L, template<class...> class P> struct mp_find_if_impl;
 
-#if BOOST_MP11_CLANG && defined( BOOST_MP11_HAS_FOLD_EXPRESSIONS )
-
-template<template<class...> class L, class... T, template<class...> class P> struct mp_find_if_impl<L<T...>, P>
-{
-    static constexpr mp_index_holder _v{ 0, false };
-    using type = mp_size_t< (_v + ... + P<T>::value).i_ >;
-};
-
-#elif !defined( BOOST_MP11_NO_CONSTEXPR )
+#if !defined( BOOST_MP11_NO_CONSTEXPR )
 
 template<template<class...> class L, template<class...> class P> struct mp_find_if_impl<L<>, P>
 {