build: switch to C++20

Signed-off-by: Patrick Williams <patrick@stwcx.xyz>
Change-Id: Ibf1de88c53762a85f105b7b3a9fbe71a434af3c5
diff --git a/meson.build b/meson.build
index fff20a7..a9d0183 100644
--- a/meson.build
+++ b/meson.build
@@ -4,12 +4,13 @@
     default_options: [
         'warning_level=3',
         'werror=true',
-        'cpp_std=c++17',
+        'cpp_std=c++20',
         'buildtype=debugoptimized',
         'prefix=/usr'
     ],
     license: 'Apache-2.0',
     version: '1.0',
+    meson_version: '>=0.57.0',
 )
 
 build_tests = get_option('tests')