payloadEqualityTraits

Functions

template<typename T>
bool supportsPayloadEquality() noexcept

Returns true if a field-wise equality comparison is defined for payload type T.

template<typename T>
bool payloadsAreEqual(const T &lhs, const T &rhs)

Compare two payloads field-wise.

Will not compile for payload types that lack a PayloadEqualityTraits<T> specialization. Guard calls with supportsPayloadEquality<T>() via if constexpr, or add a specialization.

template<typename T>
struct PayloadEqualityTraits

#include <payloadEqualityTraits.h>

Primary template: equality comparison is not supported for this payload type by default.

Native C++ code that calls recordOnChange() or payloadsAreEqual() must provide a visible PayloadEqualityTraits<T> specialization when comparison semantics can be defined safely. The generated per-payload specializations used by Python SWIG message modules are intentionally not included through messaging.h and are not part of the native C++ messaging API.

Public Static Attributes

static bool supported = false

Indicates whether equality comparison is supported for this payload type.