VSCode supports the peek function definition capability in secondary windows.

Design a toggleable secondary window below the main window of the VS Code editor. When the cursor hovers over a function name in the main window for a certain period, such as 1 second, the secondary window automatically navigates to the function definition, allowing the user to browse and edit the function within the secondary window.

This feature helps maintain a stable thought process in the main window while quickly reading through large amounts of code and developing, while the secondary window enables rapid navigation through various branches.

Both Source Insight and Microsoft Visual Studio have this capability, which is also a frequently used feature in C/C++ development.