Derelict, SDL, and OpenGL3: Triangle Tribulations

[DarthCthulhu via Digitalmars-d-learn]

So I decided to try some OGL3 stuff in D utilizing the Derelict 
bindings and SDL. Creating an SDL-OGL window worked fine, but I'm 
having trouble with doing the most basic thing of rendering a 
triangle. I get the window just fine and the screen is being 
properly cleared and buffered, but no triangle.

Code:

GLuint initVAO () {

		// An array of 3 vectors which represents 3 vertices
	static const GLfloat g_vertex_buffer_data[] = [
	  -1.0f, -1.0f, 0.0f,
	   1.0f, -1.0f, 0.0f,
	   0.0f, 1.0f, 0.0f,
	];

	// This will identify our vertex buffer
	GLuint vertexbuffer;

	// Generate 1 buffer, put the resulting identifier in 
vertexbuffer
	glGenBuffers(1, &vertexbuffer);

	// The following commands will talk about our 'vertexbuffer' 
buffer
	glBindBuffer(GL_ARRAY_BUFFER, vertexbuffer);

	// Give our vertices to OpenGL.
	glBufferData(GL_ARRAY_BUFFER, g_vertex_buffer_data.length * 
GL_FLOAT.sizeof, g_vertex_buffer_data.ptr, GL_STATIC_DRAW);

	glEnableVertexAttribArray(0);
	glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 0,  null);			
	glBindBuffer(GL_ARRAY_BUFFER, 0);
		
	return vertexbuffer;
}

void main() {

	string title = "Hello, world! With SDL2 OpenGL3.3!";
	writefln(title);

	// Create a new OGL Window
	Window win = new SDL_OGL_Window(title);

	GLuint vertexbuffer = initVAO();

	// Main loop flag
	bool quit = false;

	//Event handler
	SDL_Event e;

	glClearColor(0,0,0.4,0);

	do {
		
		glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

		glBindVertexArray(vertexbuffer);

		// Draw the triangle
		glDrawArrays(GL_TRIANGLES, 0, 3);

		glDisableVertexAttribArray(vertexbuffer);
		glBindVertexArray(0);
		
		SDL_GL_SwapWindow(win.window);

		// Handle events on queue
		while( SDL_PollEvent( &e ) != 0 ) {
			//User requests quit
			if( e.type == SDL_QUIT ) {
				quit = true;
			}
		}

		const Uint8* currentKeyStates = SDL_GetKeyboardState( null );

		// Escape to quit as well.
		if( currentKeyStates[ SDL_SCANCODE_ESCAPE ] ) {
			quit = true;;
		}

	} while ( !quit );

	glDeleteBuffers(1, &vertexbuffer);

}

The SDL_OGL_Window is an object that creates an SDL window and 
binds a OpenGL context to it; I don't think it's relevant for 
what's going on, but if anyone thinks it might be the culprit, 
I'll post it.

So, any ideas what I'm doing wrong?