Fix invalid constexpr.

Author: evoskuil

include/bitcoin/system/chain/witness.hpp

@@ -126,8 +126,8 @@ class BC_API witness
 private:
     // TODO: move to config serialization wrapper.
     static witness from_string(const std::string& mnemonic) NOEXCEPT;
-    static constexpr size_t element_size(const chunk_cptr& element) NOEXCEPT;
     static constexpr bool is_annex_pattern(const chunk_cptrs& stack) NOEXCEPT;
+    static inline size_t element_size(const chunk_cptr& element) NOEXCEPT;
     static inline bool drop_annex(chunk_cptrs& stack) NOEXCEPT;
 
     void assign_data(reader& source, bool prefix) NOEXCEPT;

include/bitcoin/system/impl/chain/witness.ipp

@@ -29,14 +29,6 @@ namespace chain {
 BC_PUSH_WARNING(SMART_PTR_NOT_NEEDED)
 BC_PUSH_WARNING(NO_VALUE_OR_CONST_REF_SHARED_PTR)
 
-// static/private
-constexpr size_t witness::element_size(const chunk_cptr& element) NOEXCEPT
-{
-    // Each witness is prefixed with number of elements [bip144].
-    const auto size = element->size();
-    return ceilinged_add(variable_size(size), size);
-};
-
 // static
 constexpr bool witness::is_push_size(const chunk_cptrs& stack) NOEXCEPT
 {
@@ -82,6 +74,14 @@ inline bool witness::drop_annex(chunk_cptrs& stack) NOEXCEPT
     return false;
 }
 
+// static/private
+inline size_t witness::element_size(const chunk_cptr& element) NOEXCEPT
+{
+    // Each witness is prefixed with number of elements [bip144].
+    const auto size = element->size();
+    return ceilinged_add(variable_size(size), size);
+};
+
 BC_POP_WARNING()
 BC_POP_WARNING()