Epeck thread safety

Algebraic_foundations/include/CGAL/Test/_test_algebraic_structure.h

@@ -338,6 +338,7 @@ void test_algebraic_structure_intern( const CGAL::Field_tag& ) {
     test_algebraic_structure_intern< AS >( CGAL::Integral_domain_tag());
      AS  a(1);
      AS  b(3);
+     AS& b_ref = b; b = b_ref; // to exercise self-copy
      AS  c = a / b;
     (void)c;  // avoid warnings for unused variables
 

Documentation/doc/Documentation/Preliminaries.txt

@@ -33,8 +33,11 @@ are:
 If the macro `CGAL_HAS_THREADS` is not defined, then \cgal assumes it can use
 any thread-unsafe code (such as static variables).  By default, this macro is not
 defined, unless `BOOST_HAS_THREADS` or `_OPENMP` is defined.  It is possible
-to force its definition on the command line, and it is possible to prevent its default
-definition by setting `CGAL_HAS_NO_THREADS` from the command line.
+to force its definition in the compiler options, and it is possible to prevent its
+default definition by defining the macro `CGAL_HAS_NO_THREADS`.
+If you are using CMake, then you can set the CMake option `CGAL_HAS_NO_THREADS` to
+`TRUE`. In addition to defining the preprocessor macro CGAL_HAS_NO_THREADS`, it will
+also avoid CMake to link with the native threads support library on your system.
 
 \section Preliminaries_cc0x C++14 Support