CI: Enable error on warnings for the extra warnings builds as an expe…

…riment. FAQ tweaks

.github/workflows/build.yml

@@ -171,22 +171,22 @@ jobs:
     - name: Build example_null (extra warnings, gcc 32-bit)
       run: |
         make -C examples/example_null clean
-        CXXFLAGS="$CXXFLAGS -m32" make -C examples/example_null EXTRA_WARNINGS=1
+        CXXFLAGS="$CXXFLAGS -m32 -Werror" make -C examples/example_null EXTRA_WARNINGS=1
 
     - name: Build example_null (extra warnings, gcc 64-bit)
       run: |
         make -C examples/example_null clean
-        CXXFLAGS="$CXXFLAGS -m64" make -C examples/example_null EXTRA_WARNINGS=1
+        CXXFLAGS="$CXXFLAGS -m64 -Werror" make -C examples/example_null EXTRA_WARNINGS=1
 
     - name: Build example_null (extra warnings, clang 32-bit)
       run: |
         make -C examples/example_null clean
-        CXXFLAGS="$CXXFLAGS -m32" CXX=clang++ make -C examples/example_null EXTRA_WARNINGS=1
+        CXXFLAGS="$CXXFLAGS -m32 -Werror" CXX=clang++ make -C examples/example_null EXTRA_WARNINGS=1
 
     - name: Build example_null (extra warnings, clang 64-bit)
       run: |
         make -C examples/example_null clean
-        CXXFLAGS="$CXXFLAGS -m64" CXX=clang++ make -C examples/example_null EXTRA_WARNINGS=1
+        CXXFLAGS="$CXXFLAGS -m64 -Werror" CXX=clang++ make -C examples/example_null EXTRA_WARNINGS=1
 
     - name: Build example_null (single file build)
       run: |

docs/FAQ.md

@@ -161,22 +161,35 @@ Interactive widgets (such as calls to Button buttons) need a unique ID.
 Unique ID are used internally to track active widgets and occasionally associate state to widgets.
 Unique ID are implicitly built from the hash of multiple elements that identify the "path" to the UI element.
 
-- Unique ID are often derived from a string label:
+- Unique ID are often derived from a string label and at minimum scoped within their host window:
 ```c
-Button("OK");          // Label = "OK",     ID = hash of (..., "OK")
-Button("Cancel");      // Label = "Cancel", ID = hash of (..., "Cancel")
+Begin("MyWindow");
+Button("OK");          // Label = "OK",     ID = hash of ("MyWindow" "OK")
+Button("Cancel");      // Label = "Cancel", ID = hash of ("MyWindow", "Cancel")
+End();
 ```
-- ID are uniquely scoped within windows, tree nodes, etc. which all pushes to the ID stack. Having
-two buttons labeled "OK" in different windows or different tree locations is fine.
-We used "..." above to signify whatever was already pushed to the ID stack previously:
+- Other elements such as tree nodes, etc. also pushes to the ID stack:
 ```c
 Begin("MyWindow");
-Button("OK");          // Label = "OK",     ID = hash of ("MyWindow", "OK")
+if (TreeNode("MyTreeNode"))
+{
+    Button("OK");      // Label = "OK",     ID = hash of ("MyWindow", "MyTreeNode", "OK")
+    TreePop();
+}
+End();
+```
+- Two items labeled "OK" in different windows or different tree locations won't collide:
+```
+Begin("MyFirstWindow");
+Button("OK");          // Label = "OK",     ID = hash of ("MyFirstWindow", "OK")
 End();
 Begin("MyOtherWindow");
 Button("OK");          // Label = "OK",     ID = hash of ("MyOtherWindow", "OK")
 End();
 ```
+
+We used "..." above to signify whatever was already pushed to the ID stack previously:
+
 - If you have a same ID twice in the same location, you'll have a conflict:
 ```c
 Button("OK");

docs/README.md

@@ -203,6 +203,7 @@ From November 2014 to December 2019, ongoing development has also been financial
 Dear ImGui is using software and services provided free of charge for open source projects:
 - [PVS-Studio](https://www.viva64.com/en/b/0570/) for static analysis.
 - [GitHub actions](https://github.com/features/actions) for continuous integration systems.
+- [OpenCppCoverage](https://github.com/OpenCppCoverage/OpenCppCoverage) for code coverage analysis.
 
 Credits
 -------