[network] Use C++17 nested namespace syntax (#14248)

esphome/components/network/ip_address.h

@@ -37,8 +37,7 @@ using ip4_addr_t = in_addr;
 #include <esp_netif.h>
 #endif
 
-namespace esphome {
-namespace network {
+namespace esphome::network {
 
 /// Buffer size for IP address string (IPv6 max: 39 chars + null)
 static constexpr size_t IP_ADDRESS_BUFFER_SIZE = 40;
@@ -187,6 +186,5 @@ struct IPAddress {
 
 using IPAddresses = std::array<IPAddress, 5>;
 
-}  // namespace network
-}  // namespace esphome
+}  // namespace esphome::network
 #endif

esphome/components/network/util.cpp

@@ -17,8 +17,7 @@
 #include "esphome/components/modem/modem_component.h"
 #endif
 
-namespace esphome {
-namespace network {
+namespace esphome::network {
 
 // The order of the components is important: WiFi should come after any possible main interfaces (it may be used as
 // an AP that use a previous interface for NAT).
@@ -109,6 +108,5 @@ const char *get_use_address() {
 #endif
 }
 
-}  // namespace network
-}  // namespace esphome
+}  // namespace esphome::network
 #endif

esphome/components/network/util.h

@@ -4,8 +4,7 @@
 #include <string>
 #include "ip_address.h"
 
-namespace esphome {
-namespace network {
+namespace esphome::network {
 
 /// Return whether the node is connected to the network (through wifi, eth, ...)
 bool is_connected();
@@ -15,6 +14,5 @@ bool is_disabled();
 const char *get_use_address();
 IPAddresses get_ip_addresses();
 
-}  // namespace network
-}  // namespace esphome
+}  // namespace esphome::network
 #endif