6.1.31 Legacy PARAMETER statements

For compatibility, GNU Fortran supports legacy PARAMETER statements without parentheses with -std=legacy. A warning is emitted if used with -std=gnu, and an error is acknowledged with a real Fortran standard flag (-std=f95, etc...). These statements take the following form:

implicit real (E)
parameter e = 2.718282
real c
parameter c = 3.0e8