Enable C++14 and add a quick check

phoenix.pro

@@ -27,6 +27,7 @@ lessThan(QT_MINOR_VERSION, 9) {
 }
 
 CONFIG += debug_and_release
+CONFIG += c++14
 
 unix:!macx {
     CONFIG += link_pkgconfig
@@ -196,6 +197,7 @@ include(pri/sketch.pri)
 include(pri/translations.pri)
 include(pri/program.pri)
 include(pri/qtsysteminfo.pri)
+include(test/version.pri)
 
 contains(DEFINES, QUAZIP_INSTALLED) {
     !build_pass:message("using installed QuaZIP library")

test/version.pri

@@ -0,0 +1,18 @@
+# /*******************************************************************
+# Part of the Fritzing project - http://fritzing.org
+# Copyright (c) 2007-2019 Fritzing
+# Fritzing is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+# Fritzing is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+# GNU General Public License for more details.
+# You should have received a copy of the GNU General Public License
+# along with Fritzing. If not, see <http://www.gnu.org/licenses/>.
+# ********************************************************************/
+
+
+SOURCES += \
+	test/version/cppversion.cpp

test/version/cppversion.cpp

@@ -0,0 +1,19 @@
+#include <iostream>
+
+/*
+  A quick compile test to verify that certain C++ features are supported
+ */
+
+template<typename T>
+constexpr T pi = T(3.1415926535897932385);
+
+void testCppVersion() {
+    int i = 1;
+    int& r = i;
+    auto ar = r;                                // int, nicht: int&
+    decltype(r) dr = r;                         // int& C++11/14
+    decltype(auto) dra = r;                     // int& C++14
+
+
+    std::cout << 0b0001'0000'0001;
+}