start Boost.Wave (links) and "fix" the numeric_limits

Author: devshgraphicsprogramming

examples_tests

@@ -262,9 +262,9 @@ struct numeric_limits : impl::numeric_limits<T> {};
 
 
 template<class T>
-struct numeric_limits : std::numeric_limits<T> 
+struct numeric_limits : std::conditional_t<std::is_same_v<T,float16_t>,IMATH_INTERNAL_NAMESPACE::limits<T>,std::numeric_limits<T>>
 {
-    using base = std::numeric_limits<T>;
+    using base = std::conditional_t<std::is_same_v<T,float16_t>,IMATH_INTERNAL_NAMESPACE::limits<T>,std::numeric_limits<T>>;
     using uint_type = std::remove_cvref_t<decltype(impl::num_traits<T>::infinity)>;
 
     NBL_CONSTEXPR_STATIC_INLINE T min = base::min();

include/nbl/builtin/hlsl/limits.hlsl

@@ -21,6 +21,10 @@
 #include <iterator>
 #include <codecvt>
 
+#include <boost/wave.hpp>
+#include <boost/wave/cpplexer/cpp_lex_token.hpp>
+#include <boost/wave/cpplexer/cpp_lex_iterator.hpp>
+
 #define TCPP_IMPLEMENTATION
 #include <tcpp/source/tcppLibrary.hpp>
 #undef TCPP_IMPLEMENTATION
@@ -225,6 +229,24 @@ DxcCompilationResult dxcCompile(const CHLSLCompiler* compiler, nbl::asset::hlsl:
 
 std::string CHLSLCompiler::preprocessShader(std::string&& code, IShader::E_SHADER_STAGE& stage, const SPreprocessorOptions& preprocessOptions) const
 {
+    using lex_token_t = boost::wave::cpplexer::lex_token<>;
+    using lex_iterator_t = boost::wave::cpplexer::lex_iterator<lex_token_t>;
+    using wave_context_t = boost::wave::context<
+        core::string::iterator,
+        lex_iterator_t,
+        boost::wave::iteration_context_policies::load_file_to_string/*,
+        TODO: OurCustomDirectiveHooks -> for pragmas and includes!
+        */
+    >;
+
+    // TODO: change `code` to `const core::string&` because its supposed to be immutable
+    wave_context_t context(code.begin(),code.end(),preprocessOptions.sourceIdentifier.data()/*,TODO: instance of OurCustomDirectiveHooks*/);
+//    context.add_include_path
+//    context.add_sysinclude_path <- for dem builtins! / preprocessOptions.includeFinder?
+//    context.add_macro_definition from preprocessOptions.extraDefines
+    core::string resolvedString;
+    // TODO: fill `resolvedString` with `[context.begin(),context.end()]`
+
     // Line 1 comes before all the extra defines in the main shader
     insertIntoStart(code, std::ostringstream(std::string(IShaderCompiler::PREPROC_DIRECTIVE_ENABLER) + "line 1\n"));
 
@@ -309,7 +331,7 @@ std::string CHLSLCompiler::preprocessShader(std::string&& code, IShader::E_SHADE
         return std::string("");
     });
 
-    auto resolvedString = proc.Process();
+    resolvedString = proc.Process();
     IShaderCompiler::reenableDirectives(resolvedString);
 
     // for debugging cause MSVC doesn't like to show more than 21k LoC in TextVisualizer