1 files changed, 32 insertions, 45 deletions

diff --git a/boost/safe_numerics/safe_base.hpp b/boost/safe_numerics/safe_base.hpp
index 7d56b8421f..55508d0d5e 100644
--- a/boost/safe_numerics/safe_base.hpp
+++ b/boost/safe_numerics/safe_base.hpp
@@ -1,11 +1,6 @@
 #ifndef BOOST_NUMERIC_SAFE_BASE_HPP
 #define BOOST_NUMERIC_SAFE_BASE_HPP
 
-// MS compatible compilers support #pragma once
-#if defined(_MSC_VER) && (_MSC_VER >= 1020)
-# pragma once
-#endif
-
 //  Copyright (c) 2012 Robert Ramey
 //
 // Distributed under the Boost Software License, Version 1.0. (See
@@ -14,10 +9,7 @@
 
 #include <limits>
 #include <type_traits> // is_integral, enable_if, conditional
-
-#include <boost/mpl/eval_if.hpp>
-#include <boost/mpl/identity.hpp>
-
+#include <boost/config.hpp> // BOOST_CLANG
 #include "concept/exception_policy.hpp"
 #include "concept/promotion_policy.hpp"
 
@@ -106,6 +98,12 @@ template<
 >
 class safe_literal_impl;
 
+// works for both GCC and clang
+#if BOOST_CLANG==1
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wmismatched-tags"
+#endif
+
 /////////////////////////////////////////////////////////////////
 // Main implementation
 
@@ -183,37 +181,9 @@ public:
 
     struct skip_validation{};
 
-    constexpr explicit safe_base(const Stored & rhs, skip_validation) :
-        m_t(rhs)
-    {}
-
-    // default constructor
-    /*
-    constexpr explicit safe_base() {
-        // this permits creating of invalid instances.  This is inline
-        // with C++ built-in but violates the premises of the whole library
-        // choice are:
-        // do nothing - violates premise of he library that all safe objects
-        // are valid
-        // initialize to valid value - violates C++ behavior of types.
-        // add "initialized" flag.  Preserves fixes the above, but doubles
-        // "overhead"
-        // still pending on this.
-    }
-    */
-    constexpr safe_base() = default;
+    constexpr explicit safe_base(const Stored & rhs, skip_validation);
 
-    // note: Rule of Five. Supply all or none of the following
-    // a) user-defined destructor
-    ~safe_base() = default;
-    // b) copy-constructor
-    constexpr safe_base(const safe_base &) = default;
-    // c) copy-assignment
-    constexpr safe_base & operator=(const safe_base &) = default;
-    // d) move constructor
-    constexpr safe_base(safe_base &&) = default;
-    // e) move assignment operator
-    constexpr safe_base & operator=(safe_base &&) = default;
+    constexpr safe_base();
 
     // construct an instance of a safe type
     // from an instance of a convertible underlying type.
@@ -225,9 +195,7 @@ public:
             is_safe<T>::value,
             bool
         >::type = true
-    ) :
-        m_t(validated_cast(t))
-    {}
+    );
 
     template<class T>
     constexpr /*explicit*/ safe_base(
@@ -236,9 +204,24 @@ public:
             std::is_integral<T>::value,
             bool
         >::type = true
-    ) :
-        m_t(validated_cast(t))
-    {}
+    );
+
+    template<class T, T value>
+    constexpr /*explicit*/ safe_base(
+        const std::integral_constant<T, value> &
+    );
+
+    // note: Rule of Five. Supply all or none of the following
+    // a) user-defined destructor
+    ~safe_base() = default;
+    // b) copy-constructor
+    constexpr safe_base(const safe_base &) = default;
+    // c) copy-assignment
+    constexpr safe_base & operator=(const safe_base &) = default;
+    // d) move constructor
+    constexpr safe_base(safe_base &&) = default;
+    // e) move assignment operator
+    constexpr safe_base & operator=(safe_base &&) = default;
 
     /////////////////////////////////////////////////////////////////
     // casting operators for intrinsic integers
@@ -359,4 +342,8 @@ public:
 
 } // std
 
+#if BOOST_CLANG==1
+#pragma GCC diagnostic pop
+#endif
+
 #endif // BOOST_NUMERIC_SAFE_BASE_HPP