build: switch to C++20

Signed-off-by: Patrick Williams <patrick@stwcx.xyz>
Change-Id: I4699bde837bcad3b9d9123bbafe0dd8bffcb97f6
diff --git a/mainloop.cpp b/mainloop.cpp
index 0b6d070..6ab8e9c 100644
--- a/mainloop.cpp
+++ b/mainloop.cpp
@@ -54,12 +54,10 @@
     &WarningObject::warningLow;
 decltype(Thresholds<WarningObject>::getHi) Thresholds<WarningObject>::getHi =
     &WarningObject::warningHigh;
-decltype(
-    Thresholds<WarningObject>::alarmLo) Thresholds<WarningObject>::alarmLo =
-    &WarningObject::warningAlarmLow;
-decltype(
-    Thresholds<WarningObject>::alarmHi) Thresholds<WarningObject>::alarmHi =
-    &WarningObject::warningAlarmHigh;
+decltype(Thresholds<WarningObject>::alarmLo)
+    Thresholds<WarningObject>::alarmLo = &WarningObject::warningAlarmLow;
+decltype(Thresholds<WarningObject>::alarmHi)
+    Thresholds<WarningObject>::alarmHi = &WarningObject::warningAlarmHigh;
 decltype(Thresholds<WarningObject>::getAlarmLow)
     Thresholds<WarningObject>::getAlarmLow = &WarningObject::warningAlarmLow;
 decltype(Thresholds<WarningObject>::getAlarmHigh)
@@ -86,12 +84,10 @@
     &CriticalObject::criticalLow;
 decltype(Thresholds<CriticalObject>::getHi) Thresholds<CriticalObject>::getHi =
     &CriticalObject::criticalHigh;
-decltype(
-    Thresholds<CriticalObject>::alarmLo) Thresholds<CriticalObject>::alarmLo =
-    &CriticalObject::criticalAlarmLow;
-decltype(
-    Thresholds<CriticalObject>::alarmHi) Thresholds<CriticalObject>::alarmHi =
-    &CriticalObject::criticalAlarmHigh;
+decltype(Thresholds<CriticalObject>::alarmLo)
+    Thresholds<CriticalObject>::alarmLo = &CriticalObject::criticalAlarmLow;
+decltype(Thresholds<CriticalObject>::alarmHi)
+    Thresholds<CriticalObject>::alarmHi = &CriticalObject::criticalAlarmHigh;
 decltype(Thresholds<CriticalObject>::getAlarmLow)
     Thresholds<CriticalObject>::getAlarmLow = &CriticalObject::criticalAlarmLow;
 decltype(Thresholds<CriticalObject>::getAlarmHigh)
diff --git a/meson.build b/meson.build
index d080492..cc27fbd 100644
--- a/meson.build
+++ b/meson.build
@@ -4,10 +4,11 @@
     default_options: [
         'warning_level=3',
         'werror=true',
-        'cpp_std=c++17'
+        'cpp_std=c++20'
     ],
     license: 'Apache-2.0',
     version: '1.0',
+    meson_version: '>=0.57.0',
 )
 
 fmt = dependency('fmt')