In Shakespeare's 9th sonnet, the speaker chooses to remain single so as not to make another woman mourn for dead husband. Shakespeare uses the word "world" (diction) as an allusion fame, needing recognition, as the love of only a wife is not enough to leave behind. There is irony of situation, that this man would choose to not have children in that they would be a constant reminder to the widow of her loss and it is better that "the world will be thy widow and still weep." Shakespeare also uses alliteration throughout the piece, "wet a widow's eye", "the world will wail thee like a makeless wife", and this gives a harsh, abrupt tone to it. He justifies this point of view with a weak parallel--money sticks around in the world after one dies--but beauty must be used or it is wasted--in conclusion, don't get married!
I respectfully disagree with the previous poster. The speaker in the sonnet is not the one who chooses to remain single and childless. The speaker is addressing another man, the "thou" (or "you") in the poem. As I read the poem, the speaker seems to be saying that the man he's talking to is too beautiful to die without first having children. To die childless would be a crime: "No love toward others in that bosom sits / That on himself such murderous shame commits."
The line "The world will wail thee, like a makeless wife" introduces at least two devices. The first, a simile, is quick and easy; it's the comparison between "world" and "wife" that begins with the word "like." The other device is personfication, the world is turned into a human-like figure, one that can experience and express emotions. This personification is the most fully developed literary device in the poem.