It is a form of ancient poetry. Generally, writing a poem of "a certain line" means that this poem is an ancient poem (line)
Is a style of classical poetry), that is to say, there is no limit to the number of words in a sentence, whether it rhymes or not, and how many sentences there are in a * * * (usually more than eight sentences). And Cao Zhi's Seven Steps Poetry is obviously a five-character quatrain (although it was not said at that time, the classification can only be assigned here. )。 Therefore, it is incorrect.
Furthermore, there were many poems in the poems before the Eastern Han Dynasty. Later, many poets in the Tang Dynasty also wrote ancient poems, generally speaking, they were written in ancient style. However, this article by Cao Zhi does not explain. Therefore, we should conclude that this poem does not belong to the line of "line".