test(sd): added .cpp build test

tools/test_apps/system/cxx_build_test/main/CMakeLists.txt

@@ -1,6 +1,7 @@
 set(srcs cxx_build_test_main.cpp
          test_soc_reg_macros.cpp
-         test_cxx_standard.cpp)
+         test_cxx_standard.cpp
+         test_sdmmc_sdspi_init.cpp)
 
 if(CONFIG_SOC_I2C_SUPPORTED)
     list(APPEND srcs test_i2c_lcd.cpp)

tools/test_apps/system/cxx_build_test/main/test_sdmmc_sdspi_init.cpp

@@ -0,0 +1,32 @@
+/*
+ * SPDX-FileCopyrightText: 2024 Espressif Systems (Shanghai) CO LTD
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+#include "soc/soc_caps.h"
+
+#if SOC_SDMMC_HOST_SUPPORTED
+#include "driver/sdmmc_host.h"
+#endif
+
+#include "driver/sdspi_host.h"
+
+
+/**
+ * Check that C-style designated initializers are valid in C++ file.
+ */
+static void test_initializers() __attribute__((unused));
+
+static void test_initializers()
+{
+#if SOC_SDMMC_HOST_SUPPORTED
+    sdmmc_host_t sdmmc_host = SDMMC_HOST_DEFAULT();
+    (void) sdmmc_host;
+    sdmmc_slot_config_t sdmmc_slot = SDMMC_SLOT_CONFIG_DEFAULT();
+    (void) sdmmc_slot;
+#endif
+    sdmmc_host_t sdspi_host = SDSPI_HOST_DEFAULT();
+    (void) sdspi_host;
+    sdspi_device_config_t sdspi_dev = SDSPI_DEVICE_CONFIG_DEFAULT();
+    (void) sdspi_dev;
+}