[gardening] Prefer isEmpty over count check

Author: ikesyo

Foundation/Data.swift

@@ -1553,7 +1553,7 @@ public struct Data : ReferenceConvertible, Equatable, Hashable, RandomAccessColl
     /// - parameter buffer: The replacement bytes.
     @inline(__always)
     public mutating func replaceSubrange<SourceType>(_ subrange: Range<Index>, with buffer: UnsafeBufferPointer<SourceType>) {
-        guard buffer.count > 0  else { return }
+        guard !buffer.isEmpty else { return }
         replaceSubrange(subrange, with: buffer.baseAddress!, count: buffer.count * MemoryLayout<SourceType>.stride)
     }
 
@@ -1635,7 +1635,7 @@ public struct Data : ReferenceConvertible, Equatable, Hashable, RandomAccessColl
         var hashValue = 0
         let hashRange: Range<Int> = _sliceRange.lowerBound..<Swift.min(_sliceRange.lowerBound + 80, _sliceRange.upperBound)
         _withStackOrHeapBuffer(hashRange.count + 1) { buffer in
-            if hashRange.count > 0 {
+            if !hashRange.isEmpty {
                 _backing.withUnsafeBytes(in: hashRange) {
                     memcpy(buffer.pointee.memory, $0.baseAddress!, hashRange.count)
                 }

Foundation/JSONEncoder.swift

@@ -283,7 +283,7 @@ fileprivate struct _JSONEncodingStorage {
     }
 
     fileprivate mutating func popContainer() -> NSObject {
-        precondition(self.containers.count > 0, "Empty container stack.")
+        precondition(!self.containers.isEmpty, "Empty container stack.")
         return self.containers.popLast()!
     }
 }
@@ -1001,7 +1001,7 @@ fileprivate struct _JSONDecodingStorage {
     }
 
     fileprivate var topContainer: Any {
-        precondition(self.containers.count > 0, "Empty container stack.")
+        precondition(!self.containers.isEmpty, "Empty container stack.")
         return self.containers.last!
     }
 
@@ -1010,7 +1010,7 @@ fileprivate struct _JSONDecodingStorage {
     }
 
     fileprivate mutating func popContainer() {
-        precondition(self.containers.count > 0, "Empty container stack.")
+        precondition(!self.containers.isEmpty, "Empty container stack.")
         self.containers.removeLast()
     }
 }

Foundation/NSArray.swift

@@ -653,7 +653,7 @@ open class NSArray : NSObject, NSCopying, NSMutableCopying, NSSecureCoding, NSCo
     }
 
     open func pathsMatchingExtensions(_ filterTypes: [String]) -> [String] {
-        guard filterTypes.count > 0 else {
+        guard !filterTypes.isEmpty else {
             return []
         }
 

Foundation/UserDefaults.swift

@@ -301,7 +301,7 @@ open class UserDefaults: NSObject {
 
         let defaultsFromDiskWithNumbersBoxed = _SwiftValue.fetch(defaultsFromDiskCF) as? [String: Any] ?? [:]
 
-        if registeredDefaultsIfAllowed.count == 0 {
+        if registeredDefaultsIfAllowed.isEmpty {
             return UserDefaults._unboxingNSNumbers(defaultsFromDiskWithNumbersBoxed) as! [String: Any]
         } else {
             var allDefaults = registeredDefaultsIfAllowed