Merge bitcoin/bitcoin#21848: refactor: Make CFeeRate constructor architecture-independent

fafd121026c4f1e25d498983e4f88c119516552b refactor: Make CFeeRate constructor architecture-independent (MarcoFalke)

Pull request description:

  Currently the constructor is architecture dependent. This is confusing for several reasons:

  * It is impossible to create a transaction larger than the max value of `uint32_t`, so a 64-bit `size_t` is not needed
  * Policy (and consensus) code should be arch-independent
  * The current code will print spurious compile errors when compiled on 32-bit systems:

  ```
  policy/feerate.cpp:23:22: warning: result of comparison of constant 9223372036854775807 with expression of type 'size_t' (aka 'unsigned int') is always true [-Wtautological-constant-out-of-range-compare]
      assert(nBytes_ <= uint64_t(std::numeric_limits<int64_t>::max()));
  ```

  Fix all issues by making it arch-independent. Also, fix `{}` style according to dev notes.

ACKs for top commit:
  theStack:
    re-ACK fafd121026c4f1e25d498983e4f88c119516552b
  promag:
    Code review ACK fafd121026c4f1e25d498983e4f88c119516552b.

Tree-SHA512: e16f75bad9ee8088b87e873906d9b5633449417a6996a226a2f37d33a2b7d4f2fd91df68998a77e52163de20b40c57fadabe7fe3502e599cbb98494178591833

1 files changed, 4 insertions, 7 deletions

diff --git a/src/policy/feerate.h b/src/policy/feerate.h
index 0e4f9914b8..d296d32774 100644
--- a/src/policy/feerate.h
+++ b/src/policy/feerate.h
@@ -39,20 +39,17 @@ public:
         // We've previously had bugs creep in from silent double->int conversion...
         static_assert(std::is_integral<I>::value, "CFeeRate should be used without floats");
     }
-    /** Constructor for a fee rate in satoshis per kvB (sat/kvB). The size in bytes must not exceed (2^63 - 1).
+    /** Constructor for a fee rate in satoshis per kvB (sat/kvB).
      *
-     *  Passing an nBytes value of COIN (1e8) returns a fee rate in satoshis per vB (sat/vB),
+     *  Passing a num_bytes value of COIN (1e8) returns a fee rate in satoshis per vB (sat/vB),
      *  e.g. (nFeePaid * 1e8 / 1e3) == (nFeePaid / 1e5),
      *  where 1e5 is the ratio to convert from BTC/kvB to sat/vB.
-     *
-     *  @param[in] nFeePaid  CAmount fee rate to construct with
-     *  @param[in] nBytes    size_t bytes (units) to construct with
      */
-    CFeeRate(const CAmount& nFeePaid, size_t nBytes);
+    CFeeRate(const CAmount& nFeePaid, uint32_t num_bytes);
     /**
      * Return the fee in satoshis for the given size in bytes.
      */
-    CAmount GetFee(size_t nBytes) const;
+    CAmount GetFee(uint32_t num_bytes) const;
     /**
      * Return the fee in satoshis for a size of 1000 bytes
      */