Enable warnings on the example target and fix one

CMakeLists.txt

@@ -12,6 +12,7 @@ endif()
 
 option(PLOTLYPP_BUILD_EXAMPLES "Build the examples" ${MAIN_PROJECT})
 option(PLOTLYPP_BUILD_MODULES "Build Plotly++ as a C++ module" OFF)
+option(PLOTLYPP_SYSTEM_INCLUDE "Include as system headers (skip for clang-tidy)." OFF)
 
 if(MAIN_PROJECT)
     set(CMAKE_EXPORT_COMPILE_COMMANDS ON)
@@ -46,6 +47,10 @@ else()
 endif()
 set(JSON_TARGET nlohmann_json::nlohmann_json)
 
+if (PLOTLYPP_SYSTEM_INCLUDE)
+    set(PLOTLYPP_INCLUDE_TYPE "SYSTEM")
+endif()
+
 if(PLOTLYPP_BUILD_MODULES)
     # Build as C++20 module
     add_library(plotlypp STATIC)
@@ -68,7 +73,7 @@ else()
 endif()
 
 target_link_libraries(plotlypp ${SCOPE} ${JSON_TARGET})
-target_include_directories(plotlypp ${SCOPE}
+target_include_directories(plotlypp ${PLOTLYPP_INCLUDE_TYPE} ${SCOPE}
     $<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}/include>
     $<INSTALL_INTERFACE:include>
 )

examples/3d_charts.cpp

@@ -122,8 +122,8 @@ Figure gen3dSurfaceTorus() {
 
     Eigen::MatrixXd u(kNumPoints, kNumPoints);
     Eigen::MatrixXd v(kNumPoints, kNumPoints);
-    for (int i = 0; i < kNumPoints; ++i) {
-        for (int j = 0; j < kNumPoints; ++j) {
+    for (auto i = 0u; i < kNumPoints; ++i) {
+        for (auto j = 0u; j < kNumPoints; ++j) {
             u(i, j) = ugrid[i][j];
             v(i, j) = vgrid[i][j];
         }

examples/CMakeLists.txt

@@ -24,6 +24,7 @@ add_library(math_utils
 target_include_directories(math_utils PUBLIC ${CMAKE_CURRENT_SOURCE_DIR})
 target_compile_features(math_utils PUBLIC cxx_std_17)
 
+include(Warnings.cmake)
 
 add_executable(example
     example.cpp
@@ -42,9 +43,22 @@ target_link_libraries(example
     Eigen3::Eigen
 )
 
+target_include_directories(example SYSTEM PRIVATE
+    $<TARGET_PROPERTY:Eigen3::Eigen,INTERFACE_INCLUDE_DIRECTORIES>
+)
+
 if(PLOTLYPP_BUILD_MODULES)
     add_executable(module_example module_example.cpp)
     target_link_libraries(module_example PRIVATE plotlypp)
     # Must use at least C++20 for modules
     target_compile_features(module_example PRIVATE cxx_std_20)
 endif()
+
+set_target_warnings(example)
+target_compile_options(example PRIVATE
+    $<$<OR:$<CXX_COMPILER_ID:Clang>,$<CXX_COMPILER_ID:AppleClang>>:
+        # Clang complains with -Wpedantic. For external users we also have the PLOTLYPP_SYSTEM_INCLUDE CMake option
+        # to treat all plotlypp headers as system headers.
+    	-Wno-overlength-strings
+    >
+)

examples/Warnings.cmake

@@ -0,0 +1,69 @@
+
+set(MSVC_WARNINGS
+    /W4 # Baseline reasonable warnings
+    # /Wall # Also warns on files included from the standard library, so it's not very useful and creates too many extra warnings.
+    /permissive-
+    /w14062 # enumerator 'identifier' in switch of enum 'enumeration' is not handled, ie -Wswitch equivalent
+    /w14242 # 'identifier': conversion from 'type1' to 'type1', possible loss of data
+    /w14254 # 'operator': conversion from 'type1:field_bits' to 'type2:field_bits', possible loss of data
+    /w14263 # 'function': member function does not override any base class virtual member function
+    /w14265 # 'classname': class has virtual functions, but destructor is not virtual instances of this class may not be destructed correctly
+    /w14287 # 'operator': unsigned/negative constant mismatch
+    /we4289 # nonstandard extension used: 'variable': loop control variable declared in the for-loop is used outside the for-loop scope
+    /w14296 # 'operator': expression is always 'boolean_value'
+    /w14311 # 'variable': pointer truncation from 'type1' to 'type2'
+    /w14545 # expression before comma evaluates to a function which is missing an argument list
+    /w14546 # function call before comma missing argument list
+    /w14547 # 'operator': operator before comma has no effect; expected operator with side-effect
+    /w14549 # 'operator': operator before comma has no effect; did you intend 'operator'?
+    /w14555 # expression has no effect; expected expression with side- effect
+    /w14619 # pragma warning: there is no warning number 'number'
+    /w14640 # Enable warning on thread un-safe static member initialization
+    /w14826 # Conversion from 'type1' to 'type_2' is sign-extended. This may cause unexpected runtime behavior.
+    /w14905 # wide string literal cast to 'LPSTR'
+    /w14906 # string literal cast to 'LPWSTR'
+    /w14928 # illegal copy-initialization; more than one user-defined conversion has been implicitly applied
+)
+
+
+set(GCC_WARNINGS
+    -Wall
+    -Wextra # reasonable and standard
+    -Wpedantic
+    -Wshadow # warn the user if a variable declaration shadows one from a parent context, may cause warnings in 3rd party libs
+    -Wnon-virtual-dtor # warn the user if a class with virtual functions has a non-virtual destructor. This helps catch hard to track down memory errors
+    -Wold-style-cast # warn for c-style casts
+    -Wcast-align # warn for potential performance problem casts
+    -Wunused # warn on anything being unused
+    -Woverloaded-virtual # warn if you overload (not override) a virtual function
+    -Wconversion # warn on type conversions that may lose data
+    -Wsign-conversion # warn on sign conversions
+    -Wnull-dereference # warn if a null dereference is detected
+    -Wdouble-promotion # warn if float is implicit promoted to double
+    -Wformat=2 # warn on security issues around functions that format output (ie printf)
+    # Maybe GCC only
+    -Wmisleading-indentation # warn if indentation implies blocks where blocks do not exist
+    -Wduplicated-cond # warn if if / else chain has duplicated conditions
+    -Wduplicated-branches # warn if if / else branches have duplicated code
+    -Wlogical-op # warn about logical operations being used where bitwise were probably wanted
+    -Wuseless-cast # warn if you perform a cast to the same type
+    -Wpedantic
+)
+
+function(set_target_warnings target_name)
+    target_compile_options(${target_name} PRIVATE
+        $<$<OR:$<CXX_COMPILER_ID:Clang>,$<CXX_COMPILER_ID:AppleClang>>:
+            -Werror
+        	-Wno-unknown-warning-option  # Silences errors for the flags below
+        	${GCC_WARNINGS}
+	    >
+	    $<$<CXX_COMPILER_ID:GNU>:
+	        -Werror
+	        ${GCC_WARNINGS}
+	    >
+        $<$<CXX_COMPILER_ID:MSVC>:
+            /WX
+            ${MSVC_WARNINGS}
+        >
+    )
+endfunction()

examples/subplots.cpp

@@ -70,7 +70,7 @@ Figure gen3dSubplots() {
 
     std::vector<std::vector<double>> z(x_grid.size(), std::vector<double>(x_grid[0].size()));
 
-    for (auto i = 0; i < x_grid.size(); ++i) {
+    for (auto i = 0u; i < x_grid.size(); ++i) {
         for (size_t j = 0; j < x_grid[0].size(); ++j) {
             double x_val = x_grid[i][j];
             double y_val = y_grid[i][j];
@@ -137,9 +137,9 @@ VolcanoData generate_data(int n) {
     std::normal_distribution<> elev_dist(1000.0, 5000.0);
     std::uniform_real_distribution<> lon_dist(-180.0, 180.0);
     std::uniform_real_distribution<> lat_dist(-70.0, 80.0);
-    std::uniform_int_distribution<> status_dist(0, 1);
-    std::uniform_int_distribution<> type_dist(0, 3);
-    std::uniform_int_distribution<> country_dist(0, 5);
+    std::uniform_int_distribution<unsigned int> status_dist(0, 1);
+    std::uniform_int_distribution<unsigned int> type_dist(0, 3);
+    std::uniform_int_distribution<unsigned int> country_dist(0, 5);
 
     std::vector<std::string> statuses = {"Historical", "Holocene"};
     std::vector<std::string> types = {"Stratovolcano", "Shield volcano", "Submarine volcano", "Caldera"};

include/plotlypp/figure.hpp

@@ -51,7 +51,7 @@ class Figure {
     void toHtml(std::ostream& os) const {
         // Serialize and sanitize for HTML embedding.
         // This escapes '<' to '\u003c' so the browser never confuses JSON data for HTML tags.
-        auto html_safe_serialize = [this](const auto& json) {
+        auto html_safe_serialize = [](const auto& json) {
             std::string s = serialize(json);
             // Escape '<' to '\u003c' so the browser never confuses JSON data for HTML tags.
             size_t pos = 0;