Hi,

Thanks for the post. You are right, the intellisense does not affect the compile. 

The compile uses real arduino but Visual Studio is not entirely capable of handling all arduino/gcc syntax.

It is work in progress, we are constantly trying to find a better way to make the intellisense work.

As an alternative you can use Visual Micro with Atmel Studio which is based on Visual Studio and is free. 

Atmel Studio is built to understand the Arduino syntax.

Atmel Studio uses the Visual Studio Shell which does not include a C++ compiler.

Atmel installs with the VisualAssistX extension already configured. It is Visual Assist that provides the Gcc compatible intellisense for the Atmel Gcc toolchain. The Arduino Ide also uses a version of the atmel toolchain which is installed when you install arduino.

The Microsoft C++ compiler expects Microsoft C++ syntax which is close but not 100% compatible. Especially when you use the lower level syntax that you have used.

ok but one thing to note is that after installing atmel or any other vs ide. Run the visual micro installer and click remove, then run and again and click install. Your settings will be preserved but it ensures we are registered with the new ide (all installed ide's) correctly.