Merge release/1.18 into master

Author: straight-shoota

src/fiber/execution_context.cr

@@ -92,18 +92,16 @@ module Fiber::ExecutionContext
   # parallel execution context for example.
   #
   # Respects the `CRYSTAL_WORKERS` environment variable if present and valid,
-  # and otherwise defaults to the minimum number of logical CPUs available to
-  # the process or available on the computer.
+  # and otherwise defaults to the number of logical CPUs available to the
+  # process or on the computer.
   def self.default_workers_count : Int32
-    if count = ENV["CRYSTAL_WORKERS"]?.try(&.to_i?)
-      return count.clamp(1..)
-    end
-
-    total = System.cpu_count.to_i.clamp(1..)
-    effective = Crystal::System.effective_cpu_count.to_i.clamp(1..)
+    count = ENV["CRYSTAL_WORKERS"]?.try(&.to_i?) || -1
+    count = Crystal::System.effective_cpu_count.to_i if count == -1
+    count = System.cpu_count.to_i if count == -1
     # TODO: query for CPU limits (e.g. linux/cgroup, freebsd/rctl, ...)
 
-    Math.min(total, effective)
+    # always report at least 1 worker
+    count.clamp(1..)
   end
 
   # :nodoc:

src/io.cr

@@ -930,7 +930,7 @@ abstract class IO
   # io.rewind
   # io.read_bytes(Int32, IO::ByteFormat::LittleEndian) # => 0x01020304
   # ```
-  def read_bytes(type : T.class, format : IO::ByteFormat = IO::ByteFormat::SystemEndian) : T forall T
+  def read_bytes(type, format : IO::ByteFormat = IO::ByteFormat::SystemEndian)
     type.from_io(self, format)
   end