stabilize build system: depends, installer, boost/bdb fixes, cross targets groundwork

2026-02-24 18:38:47 +00:00
parent da8c28aaeb
commit 65cb2619a7
13106 changed files with 2484322 additions and 1804 deletions
@@ -0,0 +1,40 @@
+/// @file
+// Copyright (c) 2009-2016 Vladimir Batov.
+// Use, modification and distribution are subject to the Boost Software License,
+// Version 1.0. See http://www.boost.org/LICENSE_1_0.txt.
+
+#ifndef BOOST_MAKE_DEFAULT_HPP
+#define BOOST_MAKE_DEFAULT_HPP
+
+namespace boost
+{
+    /// @details A considerable number of libraries require an instance of a class
+    /// provided (storage created and initialized). For example,
+    /// @code
+    ///    Type result;
+    ///    ...
+    ///    istream >> result;
+    /// @endcode
+    /// In generic code that results in the Default Constructibility requirement imposed
+    /// on every type 'Type' to be used with the respective code. Inevitably, that requirement
+    /// a) either excludes all the classes that for various reasons do not meet that requirement or
+    /// b) imposes certain (not necessarily desirable) design/implementation onto respective classes.
+    ///
+    /// Deployment of boost::make_default() eliminates the Default Constructibility requirement with
+    /// @code
+    ///    Type result = boost::make_default<Type>();
+    ///    ...
+    ///    istream >> result;
+    /// @endcode
+    /// Classes with no default constructor can now be included via a boost::make_default() specialization:
+    /// @code
+    /// namespace boost
+    /// {
+    ///     template<> inline Type make_default<Type>() { return Type(parameters); }
+    /// }
+    /// @endcode
+
+    template<typename T> T make_default() { return T(); }
+}
+
+#endif // BOOST_MAKE_DEFAULT_HPP