Don't fail file open/writes silently (#880)

Author: asklar

cppwinrt/main.cpp

@@ -8,6 +8,7 @@
 #include "component_writers.h"
 #include "file_writers.h"
 #include "type_writers.h"
+#include <winternl.h>
 
 namespace cppwinrt
 {
@@ -374,5 +375,7 @@ Where <spec> is one or more of:
 
 int main(int const argc, char** argv)
 {
+    // Dynamically enable long path support
+    ((unsigned char*)(NtCurrentTeb()->ProcessEnvironmentBlock))[3] |= 0x80;
     return cppwinrt::run(argc, argv);
 }

cppwinrt/text_writer.h

@@ -157,9 +157,18 @@ namespace cppwinrt
         {
             if (!file_equal(filename))
             {
-                std::ofstream file{ filename, std::ios::out | std::ios::binary };
-                file.write(m_first.data(), m_first.size());
-                file.write(m_second.data(), m_second.size());
+                std::ofstream file;
+                file.exceptions(std::ofstream::failbit | std::ofstream::badbit);
+                try
+                {
+                  file.open(filename, std::ios::out | std::ios::binary);
+                  file.write(m_first.data(), m_first.size());
+                  file.write(m_second.data(), m_second.size());
+                }
+                catch (std::ofstream::failure const& e)
+                {
+                  throw std::filesystem::filesystem_error(e.what(), filename, std::io_errc::stream);
+                }
             }
             m_first.clear();
             m_second.clear();