Clarify monitor reference documentation
Related to #594.
diff --git a/include/GLFW/glfw3.h b/include/GLFW/glfw3.h
index 7992de3..f14900f 100644
--- a/include/GLFW/glfw3.h
+++ b/include/GLFW/glfw3.h
@@ -1212,12 +1212,13 @@
/*! @brief Returns the currently connected monitors.
*
* This function returns an array of handles for all currently connected
- * monitors.
+ * monitors. The primary monitor is always first in the returned array. If no
+ * monitors were found, this function returns `NULL`.
*
* @param[out] count Where to store the number of monitors in the returned
* array. This is set to zero if an error occurred.
- * @return An array of monitor handles, or `NULL` if an
- * [error](@ref error_handling) occurred.
+ * @return An array of monitor handles, or `NULL` if no monitors were found or
+ * if an [error](@ref error_handling) occurred.
*
* @par Pointer Lifetime
* The returned array is allocated and freed by GLFW. You should not free it
@@ -1240,14 +1241,17 @@
/*! @brief Returns the primary monitor.
*
* This function returns the primary monitor. This is usually the monitor
- * where elements like the Windows task bar or the OS X menu bar are located.
+ * where elements like the task bar or global menu bar are located.
*
- * @return The primary monitor, or `NULL` if an [error](@ref error_handling)
- * occurred.
+ * @return The primary monitor, or `NULL` if no monitors were found or if an
+ * [error](@ref error_handling) occurred.
*
* @par Thread Safety
* This function may only be called from the main thread.
*
+ * @remarks The primary monitor is always first in the array returned by @ref
+ * glfwGetMonitors.
+ *
* @sa @ref monitor_monitors
* @sa glfwGetMonitors
*
