build(wasm): libconstants can now compile to wasm and run as a wasm module

cross/macos_arm64.ini

@@ -0,0 +1,19 @@
+[binaries]
+c = 'arm64-apple-darwin25-clang'
+cpp = 'arm64-apple-darwin25-clang++'
+ar = 'arm64-apple-darwin25-ar'
+strip = 'arm64-apple-darwin25-strip'
+pkg-config = 'pkg-config'
+ranlib = '/usr/bin/true'
+
+[host_machine]
+system = 'darwin'
+cpu_family = 'aarch64'
+cpu = 'arm64'
+endian = 'little'
+
+[built-in options]
+c_args = ['-mmacosx-version-min=15.0']
+cpp_args = ['-mmacos-version-min=15.0']
+c_link_args = ['-mmacosx-version-min=15.0']
+cpp_link_args = ['-mmacos-version-min=15.0']

cross/wasm.ini

@@ -0,0 +1,19 @@
+[binaries]
+cpp = 'em++'
+ar = 'emar'
+strip = 'emstrip'
+
+exec_wrapper = 'node'
+
+[built-in options]
+cpp_args = ['-Dpkg_config=false', '-Dbuild_tests=false', '-Dbuild_examples=true', '-fwasm-exceptions', '-s', 'MEMORY64=1']
+cpp_link_args = ['-s', 'WASM=1', '-s', 'ALLOW_MEMORY_GROWTH=1', '-s', 'MEMORY64=1', '-fwasm-exceptions']
+
+[host_machine]
+system = 'emscripten'
+cpu_family = 'wasm64'
+cpu = 'wasm64'
+endian = 'little'
+
+[properties]
+cmake_toolchain_file = '/home/tboudreaux/Programming/emsdk/upstream/emscripten/cmake/Modules/Platform/Emscripten.cmake'

examples/meson.build

@@ -0,0 +1 @@
+executable('simple_constant_usage', 'simple.cpp', dependencies: [const_dep])

examples/simple.cpp

@@ -0,0 +1,13 @@
+#include "fourdst/constants/const.h"
+#include <iostream>
+
+int main() {
+  fourdst::constant::Constants& C = fourdst::constant::Constants::getInstance();
+  
+  std::cout << "Speed of light is " << C.get("c") << std::endl;
+  std::cout << "All avalible constants are: ";
+
+  for (const auto& key : C.keys()) {
+    std::cout << "\t " << key << ": " << C[key];
+  }
+}

meson.build

@@ -28,9 +28,16 @@ cpp = meson.get_compiler('cpp')
 subdir('assets/static')
 
 subdir('src')
-subdir('tests')
 
-if get_option('pkg-config')
+if get_option('build_tests')
+  subdir('tests')
+endif
+
+if get_option('build_examples')
+  subdir('examples')
+endif
+
+if get_option('pkg_config')
     message('Generating pkg-config file for libconstants...')
     pkg = import('pkgconfig')
     pkg.generate(

meson_options.txt

@@ -1 +1,3 @@
-option('pkg-config', type: 'boolean', value: true, description: 'generate pkg-config file for libconstants (fourdst_constants.pc)')
+option('pkg_config', type: 'boolean', value: true, description: 'generate pkg-config file for libconstants (fourdst_constants.pc)')
+option('build_tests', type: 'boolean', value: true, description: 'control if tests are built or not')
+option('build_examples', type: 'boolean', value: true, description: 'control if examples is built or not')

src/constants/lib/const.cpp

@@ -20,11 +20,10 @@
 // *********************************************************************** */
 #include <iostream>
 #include <map>
-#include <vector>
 #include <string>
-#include <fstream>
 #include <sstream>
 #include <set>
+#include <exception>
 
 
 #include "fourdst/constants/const.h"