It doesn't just have to be files, FWIW. I once worked in a Go project which used SDL through CGO for drawing. "Widgets" were basically functions which would allocate an SDL surface, draw to it using Cairo, and return it to Go code. That SDL surface would be wrapped in a Go wrapper with a Destroy method which would call SDL_DestroySurface.

And to draw a surface to the screen, you need to create an SDL texture from it. If that's all you want to do, you can then destroy the SDL surface.

So you could imagine code like this:

    strings := []string{"Lorem", "ipsum", "dolor", "sit", "amet"}
    
    stringTextures := []SDLTexture{}
    for _, s := range strings {
        surface := RenderTextToSurface(s)
        defer surface.Destroy()
        stringTextures = append(stringTextures, surface.CreateTexture())
    }

Files are IO, which means a lot of waiting. For what reason wouldn't you want to open them concurrently?