Also compile pbori with c+11 for old boost

Author: tobiasdiez

src/meson.build

@@ -214,6 +214,27 @@ endif
 # Cannot be found via pkg-config
 ntl = cc.find_library('ntl', required: not is_windows, disabler: true)
 
+boost_cpp17_compatible = false
+boost = dependency(
+  'boost',
+  version: '>=1.83.0',
+  required: false,
+  modules: ['graph', 'tuple'],
+)
+if boost.found()
+  # Need at least v1.83.0 (https://github.com/boostorg/functional/commit/6a573e4b8333ee63ee62ce95558c3667348db233)
+  # for C++17 compatibility.
+  boost_cpp17_compatible = true
+else
+  boost = dependency(
+    'boost',
+    version: '>=1.66.0',
+    required: false,
+    modules: ['graph', 'tuple'],
+  )
+endif
+
+
 # Meson currently ignores include_directories for Cython modules, so we
 # have to add them manually.
 # https://github.com/mesonbuild/meson/issues/9562

src/sage/graphs/base/meson.build

@@ -1,23 +1,3 @@
-boost_cpp17_compatible = false
-boost = dependency(
-  'boost',
-  version: '>=1.83.0',
-  required: false,
-  modules: ['graph', 'tuple'],
-)
-if boost.found()
-  # Need at least v1.83.0 (https://github.com/boostorg/functional/commit/6a573e4b8333ee63ee62ce95558c3667348db233)
-  # for C++17 compatibility.
-  boost_cpp17_compatible = true
-else
-  boost = dependency(
-    'boost',
-    version: '>=1.66.0',
-    required: false,
-    modules: ['graph', 'tuple'],
-  )
-endif
-
 py.install_sources(
   '__init__.py',
   'all.py',

src/sage/rings/polynomial/pbori/meson.build

@@ -33,14 +33,27 @@ py.install_sources(
 extension_data_cpp = {'pbori': files('pbori.pyx')}
 
 foreach name, pyx : extension_data_cpp
+  override_options = ['cython_language=cpp']
+  if not boost_cpp17_compatible
+    override_options += ['cpp_std=c++11']
+  endif
   py.extension_module(
     name,
     sources: pyx,
     subdir: 'sage/rings/polynomial/pbori',
     install: true,
-    override_options: ['cython_language=cpp'],
+    override_options: override_options,
     include_directories: [inc_cpython, inc_ext, inc_rings, inc_src],
-    dependencies: [py_dep, brial, brial_groebner, cysignals, gmp, m4ri, png],
+    dependencies: [
+      py_dep,
+      boost,
+      brial,
+      brial_groebner,
+      cysignals,
+      gmp,
+      m4ri,
+      png,
+    ],
   )
 endforeach