[core] Add cg.byte_span for std::span<const uint8_t> (#22462)

esphome/codegen.py

@@ -92,6 +92,7 @@ from esphome.cpp_types import (  # noqa: F401
     StringRef,
     arduino_json_ns,
     bool_,
+    byte_span,
     char,
     const_char_ptr,
     double,

esphome/cpp_types.py

@@ -24,6 +24,7 @@ int16 = global_ns.namespace("int16_t")
 int32 = global_ns.namespace("int32_t")
 int64 = global_ns.namespace("int64_t")
 size_t = global_ns.namespace("size_t")
+byte_span = std_span.template(uint8.operator("const"))
 const_char_ptr = global_ns.namespace("const char *")
 NAN = global_ns.namespace("NAN")
 esphome_ns = global_ns  # using namespace esphome;

tests/unit_tests/test_codegen.py

@@ -77,6 +77,10 @@ def test_exists(attr):
     assert hasattr(cg, attr)
 
 
+def test_byte_span() -> None:
+    assert str(cg.byte_span) == "std::span<const uint8_t>"
+
+
 @pytest.mark.parametrize(
     ("type_str", "expected"),
     (