Use a separate (non-trait) fee-estimation fn in LowerBoundedEstimator

This should make it somewhat more difficult to accidentally use a
straight fee estimator when we actually want a
LowerBoundedFeeEstimator by not having the types be exchangeable at
all.

diff --git a/lightning/src/chain/chaininterface.rs b/lightning/src/chain/chaininterface.rs
index 2ec7f318ff57bb5a3e798a0ecd651cc1fb5f4e1d..ab659cbca1341a36f88d2e005091300c4d350ff4 100644 (file)
--- a/lightning/src/chain/chaininterface.rs
+++ b/lightning/src/chain/chaininterface.rs
@@ -68,7 +68,10 @@ pub const MIN_RELAY_FEE_SAT_PER_1000_WEIGHT: u64 = 4000;
 pub const FEERATE_FLOOR_SATS_PER_KW: u32 = 253;
 
 /// Wraps a `Deref` to a `FeeEstimator` so that any fee estimations provided by it
-/// are bounded below by `FEERATE_FLOOR_SATS_PER_KW` (253 sats/KW)
+/// are bounded below by `FEERATE_FLOOR_SATS_PER_KW` (253 sats/KW).
+///
+/// Note that this does *not* implement [`FeeEstimator`] to make it harder to accidentally mix the
+/// two.
 pub(crate) struct LowerBoundedFeeEstimator<F: Deref>(pub F) where F::Target: FeeEstimator;
 
 impl<F: Deref> LowerBoundedFeeEstimator<F> where F::Target: FeeEstimator {
@@ -76,10 +79,8 @@ impl<F: Deref> LowerBoundedFeeEstimator<F> where F::Target: FeeEstimator {
        pub fn new(fee_estimator: F) -> Self {
                LowerBoundedFeeEstimator(fee_estimator)
        }
-}
 
-impl<F: Deref> FeeEstimator for LowerBoundedFeeEstimator<F> where F::Target: FeeEstimator {
-       fn get_est_sat_per_1000_weight(&self, confirmation_target: ConfirmationTarget) -> u32 {
+       pub fn get_est_sat_per_1000_weight(&self, confirmation_target: ConfirmationTarget) -> u32 {
                cmp::max(
                        self.0.get_est_sat_per_1000_weight(confirmation_target),
                        FEERATE_FLOOR_SATS_PER_KW,