meson: check if ublas compiles

apps/meson.build

@@ -54,6 +54,24 @@ cpp_can_link_with_boost_program_options = cpp_compiler.links(
   dependencies: boost_program_options_dep,
 )
 
+boost_ublas_code = '''
+#include <boost/numeric/ublas/matrix.hpp>
+#include <boost/numeric/ublas/io.hpp>
+int main (int argc, char* argv[]) {
+     using namespace boost::numeric::ublas;
+     matrix m (3, 3);
+     for (unsigned i = 0; i < m.size1 (); ++ i)
+         for (unsigned j = 0; j < m.size2 (); ++ j)
+             m (i, j) = 3 * i + j;
+     std::cout << m << std::endl;
+}
+'''
+cpp_can_link_with_boost_ublas = cpp_compiler.links(
+  boost_ublas_code,
+  name: 'boost_ublas',
+  dependencies: boost_dep,
+)
+
 if (not automagic) or cpp_can_link_with_boost_program_options
   fib_child_stealing_exe = executable(
     'fib-child-stealing',
@@ -61,11 +79,13 @@ if (not automagic) or cpp_can_link_with_boost_program_options
     dependencies: [emper_dep, boost_program_options_dep],
   )
 
-  mat_mul_exe = executable(
-    'mat-mul',
-    'MatMul.cpp',
-    dependencies: [emper_dep, boost_dep, boost_program_options_dep],
-  )
+  if (not automagic) or cpp_can_link_with_boost_ublas
+    mat_mul_exe = executable(
+      'mat-mul',
+      'MatMul.cpp',
+      dependencies: [emper_dep, boost_dep, boost_program_options_dep],
+    )
+  endif
 endif
 
 subdir('fsearch')