Add tests for quick_allocator

test/Jamfile

@@ -429,3 +429,6 @@ run sp_type_with_alignment_test.cpp ;
 run sp_ostream_test.cpp ;
 run ip_ostream_test.cpp ;
 run lsp_ostream_test.cpp ;
+
+run shared_ptr_alloc_test.cpp ;
+run quick_allocator_test.cpp ;

test/quick_allocator_test.cpp

@@ -0,0 +1,83 @@
+// Copyright 2025 Peter Dimov
+// Distributed under the Boost Software License, Version 1.0.
+// https://www.boost.org/LICENSE_1_0.txt
+
+#include <boost/smart_ptr/detail/quick_allocator.hpp>
+#include <boost/core/lightweight_test.hpp>
+#include <cstring>
+
+// The interface of quick_allocator has never been documented,
+// but in can be inferred from the source code to be
+//
+// template<class T> struct quick_allocator
+// {
+//     // allocate memory for an object of type T
+//     static void* alloc();
+//
+//     // deallocate the memory returned from alloc()
+//     static void dealloc( void* p );
+//
+//     // if n == sizeof(T), returns alloc()
+//     // otherwise, allocates a memory block of size n
+//     static void* alloc( std::size_t n );
+//
+//     // deallocate the memory returned from alloc( n )
+//     static void dealloc( void* p, std::size_t n );
+//  };
+
+struct X
+{
+    int data;
+};
+
+struct Y: public X
+{
+    int data2;
+};
+
+int main()
+{
+    using boost::detail::quick_allocator;
+
+    void* p = quick_allocator<Y>::alloc();
+    std::memset( p, 0xAA, sizeof(Y) );
+
+    {
+        void* p1 = quick_allocator<X>::alloc();
+        std::memset( p1, 0xCC, sizeof(X) );
+
+        void* p2 = quick_allocator<X>::alloc();
+        std::memset( p2, 0xDD, sizeof(X) );
+
+        BOOST_TEST_NE( p1, p2 );
+        BOOST_TEST_EQ( *static_cast<unsigned char*>( p1 ), 0xCC );
+        BOOST_TEST_EQ( *static_cast<unsigned char*>( p2 ), 0xDD );
+
+        quick_allocator<X>::dealloc( p1 );
+        BOOST_TEST_EQ( *static_cast<unsigned char*>( p2 ), 0xDD );
+
+        quick_allocator<X>::dealloc( p2 );
+    }
+
+    {
+        void* p1 = quick_allocator<X>::alloc( sizeof(X) );
+        std::memset( p1, 0xCC, sizeof(X) );
+
+        void* p2 = quick_allocator<X>::alloc( sizeof(Y) );
+        std::memset( p2, 0xDD, sizeof(Y) );
+
+        BOOST_TEST_NE( p1, p2 );
+        BOOST_TEST_EQ( *static_cast<unsigned char*>( p1 ), 0xCC );
+        BOOST_TEST_EQ( *static_cast<unsigned char*>( p2 ), 0xDD );
+
+        quick_allocator<X>::dealloc( p1, sizeof(X) );
+        BOOST_TEST_EQ( *static_cast<unsigned char*>( p2 ), 0xDD );
+
+        quick_allocator<X>::dealloc( p2, sizeof(Y) );
+    }
+
+    BOOST_TEST_EQ( *static_cast<unsigned char*>( p ), 0xAA );
+    quick_allocator<Y>::dealloc( p );
+
+    return boost::report_errors();
+}