Add static_assert to is_sorted() for the lookup tables in validate.cpp (#650)

Co-authored-by: Sumit Bhardwaj <subhardw@microsoft.com>

tools/CMakeLists.txt

@@ -4,7 +4,7 @@
 cmake_minimum_required(VERSION 3.15)
 project(msvc_standard_libraries_tools LANGUAGES CXX)
 
-set(CMAKE_CXX_STANDARD 17)
+set(CMAKE_CXX_STANDARD 20)
 set(CMAKE_CXX_STANDARD_REQUIRED True)
 set(CMAKE_MSVC_RUNTIME_LIBRARY "MultiThreaded$<$<CONFIG:Debug>:Debug>")
 

tools/validate/validate.cpp

@@ -172,10 +172,9 @@ int main() {
         ".gitmodules"sv,
     };
 
-    // TRANSITION, P0202R3, use constexpr is_sorted()
-    assert(is_sorted(skipped_directories.begin(), skipped_directories.end()));
-    assert(is_sorted(skipped_extensions.begin(), skipped_extensions.end()));
-    assert(is_sorted(tabby_filenames.begin(), tabby_filenames.end()));
+    static_assert(is_sorted(skipped_directories.begin(), skipped_directories.end()));
+    static_assert(is_sorted(skipped_extensions.begin(), skipped_extensions.end()));
+    static_assert(is_sorted(tabby_filenames.begin(), tabby_filenames.end()));
 
     vector<unsigned char> buffer; // reused for performance