YASnippets for all standard includes in the C++ standard.
Either add the location of the snippet directory to yas-snippet-dirs or place the directory inside a directory in this path.
(add-to-list 'yas-snippet-dirs "<snippets_directory>")
The snippets will be active for c++-mode and will be added to the includes sub-group (assuming you named the directory includes).
As I work with different standard library implementations which don't all use the std namespace, I have a function that returns the appropriate include path for the current file. If you are only using a standard library implementation provided by your compiler vendor either just return "<include-path>" from the function or replace the call in the snippets.
Add the following function to your configuration:
(defun rcj-cc-mode-std-include-directive-for-file (include-path) (concat "<" include-path ">"))
cd <snippet-directory> && sed -i 's/`(rcj-cc-mode-std-include-directive-for-file "\(.*\?\)")`/<\1>/'