Function overnight_hull_white_rate 

fn overnight_hull_white_rate<R: Scalar>(
    strip: &AnyCoupon,
    rate: R,
    view: &PricingView<'_, R>,
) -> Result<R, PricingError>

An overnight contract’s futures rate under Hull–White, from its strip rate rate (realised days read, the rest projected, no convexity).

Compounded: 1 + τF_fut = (1 + τF_strip)·e^Λ, Λ the compounded exponent from the first day whose print is not held to the accrual end — Mercurio’s in-arrears expectation, the realised growth a known factor.

Averaged: each print still to fix is a simple rate over its own window, whose expectation is the term contract’s E[1/P(t, t′)] = P(0, t)/P(0, t′)·e^{Λ_term}; its convexity is added at the weight the strip gives it.

Model time is ACT/365F from the valuation date, as for a term contract.