Document BOOST_CORE_STATIC_ASSERT

doc/changes.qbk

@@ -17,6 +17,8 @@
   and `std::size`, respectively, when the latter are provided by compiler. This resolves potential
   ambiguities when both `boost::` and `std::` alternatives are found by the compiler, e.g. as a result
   of ADL. ([github_issue 206])
+* Added [link core.static_assert `BOOST_CORE_STATIC_ASSERT`], a reimplementation of `BOOST_STATIC_ASSERT`
+  for libraries that already depend on Core and would like to remove the dependency on StaticAssert.
 
 [endsect]
 

doc/core.qbk

@@ -81,6 +81,7 @@ criteria for inclusion is that the utility component be:
 [include serialization.qbk]
 [include size.qbk]
 [include span.qbk]
+[include static_assert.qbk]
 [include swap.qbk]
 [include typeinfo.qbk]
 [include type_name.qbk]

doc/static_assert.qbk

@@ -0,0 +1,57 @@
+[/
+  Copyright 2025 Peter Dimov
+  Distributed under the Boost Software License, Version 1.0.
+  https://boost.org/LICENSE_1_0.txt
+]
+
+[section:static_assert static_assert]
+
+[simplesect Authors]
+
+* Peter Dimov
+
+[endsimplesect]
+
+[section Header <boost/core/static_assert.hpp>]
+
+The header `<boost/core/static_assert.hpp>` defines
+the macro `BOOST_CORE_STATIC_ASSERT(expr)`, which
+expands to `static_assert(expr, #expr)` under C++11
+or later, or to a suitable emulation under C++03.
+
+The same functionality is provided by `BOOST_STATIC_ASSERT`
+defined in `<boost/static_assert.hpp>`, and the macro
+is duplicated here for libraries that already depend
+on Core and would like to remove the dependency on
+StaticAssert.
+
+[section Synopsis]
+
+``
+#define BOOST_CORE_STATIC_ASSERT(expr) static_assert(expr, #expr)
+``
+
+[endsect]
+
+[section Example]
+
+```
+#include <boost/core/static_assert.hpp>
+
+BOOST_CORE_STATIC_ASSERT( sizeof(char[1]) == 1 );
+
+struct X
+{
+    BOOST_CORE_STATIC_ASSERT( sizeof(char[2]) == 2 );
+};
+
+int main()
+{
+    BOOST_CORE_STATIC_ASSERT( sizeof(char[3]) == 3 );
+}
+```
+[endsect]
+
+[endsect]
+
+[endsect]