-PB_MAX_REQUIRED_FIELDS Maximum number of required fields to check for presence. Default value is 64.
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+PB_MAX_REQUIRED_FIELDS Maximum number of required fields to check for presence. Default value is 64. Increases stack
+ usage 1 byte per every 8 fields. Compiler warning will tell if you need this.
+PB_FIELD_16BIT Add support for tag numbers > 255 and fields larger than 255 bytes or 255 array entries.
+ Increases code size 3 bytes per each field. Compiler error will tell if you need this.
+PB_FIELD_32BIT Add support for tag numbers > 65535 and fields larger than 65535 bytes or 65535 array entries.
+ Increases code size 9 bytes per each field. Compiler error will tell if you need this.
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+
+The PB_MAX_REQUIRED_FIELDS, PB_FIELD_16BIT and PB_FIELD_32BIT settings allow raising some datatype limits to suit larger messages.
+Their need is recognized automatically by C-preprocessor #if-directives in the generated .pb.h files. The default setting is to use
+the smallest datatypes (least resources used).