bump C++ standard to C++-14, newer libprotobuf have a hard minimum C++-14 requirement. this should enable builds with libprotobuf installed on MacOS 15 and after

Author: patrickbr

.github/workflows/build.yml

@@ -187,3 +187,18 @@ jobs:
         run: cd build && make
       - name: tests
         run: cd build && ctest --output-on-failure
+  macos-26-protobuf-build:
+    runs-on: macos-26
+    steps:
+      - name: Checkout repository code
+        uses: actions/checkout@v2
+      - name: Checkout submodules
+        run: git submodule update --init --recursive
+      - name: install dependencies
+        run: brew install --force --overwrite cmake && brew install --force --overwrite glpk && brew tap coin-or-tools/coinor && brew install --force --overwrite coin-or-tools/coinor/cbc && brew install protobuf
+      - name: cmake
+        run: mkdir build && cd build && cmake ..
+      - name: make
+        run: cd build && make
+      - name: tests
+        run: cd build && ctest --output-on-failure

CMakeLists.txt

@@ -1,5 +1,5 @@
 cmake_minimum_required (VERSION 3.5)
-set(CMAKE_CXX_STANDARD 11)
+set(CMAKE_CXX_STANDARD 14)
 
 project (loom)
 

README.md

@@ -21,7 +21,7 @@ Requirements
 ------------
 
  * `cmake`
- * `gcc >= 5.0` (or `clang >= 3.9`)
+ * `gcc >= 5.1` (or `clang >= 3.9`)
  * Optional: `libglpk-dev` (ILP solver), `coinor-libcbc-dev` (ILP solver), `gurobi` (ILP solver), `libzip-dev`, `libprotobuf-dev` + `protobuf-compiler` (for vector tile output)