In a very formal style, think is sometimes followed by an object and an adjective or noun complement.
They thought her fascinating.
We thought him a fool.(M. Swan, Practical English Usage, 588.4)
It says 'very formal,' but my old dictionary says the structure, without 'to be,' happens in speech.
How should I understand these? Does this 'formal' mean... I don't know if this is a reasonable word... form-oriented? I mean it's like form for form sake? What is the word for it?