Update comments

src/mask.h

@@ -1,14 +1,20 @@
-#include <algorithm>
+#include <cstddef>
 
-template<typename T> constexpr T mask(size_t bits, size_t offset = 0) {
-    return (((T)1 << bits) - 1) << offset;
+// Returns an instance of T with the given number of bits set to 1, starting at the given offset
+template<typename T> constexpr T mask(size_t num_bits, size_t offset = 0) {
+    return (((T)1 << num_bits) - 1) << offset;
 }
 
-template<typename T> constexpr T get_masked(T data, size_t bits, size_t offset) {
-    return (data >> offset) & mask<T>(bits);
+// Returns the given number of bits from the data parameter, starting at the given offset
+template<typename T> constexpr T get_masked(T data, size_t num_bits, size_t offset) {
+    return (data >> offset) & mask<T>(num_bits);
 }
 
+/**
+ * Returns a copy of the given data with the given number of bits (starting at the given offset)
+ * set to match the given binary value
+ */
 //TODO: support typeof(data) != typeof(value)?
-template<typename T> constexpr T set_masked(T data, T value, size_t bits, size_t offset) {
-    return (data & ~mask<T>(bits, offset)) | ((value & mask<T>(bits)) << offset);
+template<typename T> constexpr T set_masked(T data, T value, size_t num_bits, size_t offset) {
+    return (data & ~mask<T>(num_bits, offset)) | ((value & mask<T>(num_bits)) << offset);
 }

src/short_phone_number.h

@@ -5,10 +5,16 @@
 
 #include "mask.h"
 
+/**
+ * Raised when a phone number is too long to fit in a ShortPhoneNumber
+ * 
+ * This shouldn't happen for any valid phone numbers.
+ */
 class PhoneNumberTooLongException : public std::runtime_error {
     public:
     PhoneNumberTooLongException(const i18n::phonenumbers::PhoneNumber& number, const char* msg);
 
+    /// Returns the original phone number object
     i18n::phonenumbers::PhoneNumber number() const {
         return _number;
     }
@@ -27,18 +33,24 @@ class PhoneNumberTooLongException : public std::runtime_error {
 class ShortPhoneNumber {
     public:
     enum : size_t {
+        /// The largest possible country code
         MAX_COUNTRY_CODE = 999,
+        /// The maximum number of leading zeroes in a national phone number
         MAX_LEADING_ZEROS = 15,
-        //15 digits
+        /// The largest possible national number
         MAX_NATIONAL_NUMBER = 999999999999999,
     };
 
     enum : size_t {
+        /// The number of bits reserved for a country code
         COUNTRY_CODE_BITS = 10,
+        /// The number of bits reserved for the leading zero count
         LEADING_ZEROS_BITS = 4,
+        /// The number of bits reserved for the national number
         NATIONAL_NUMBER_BITS = 50,
     };
 
+    // Bit offsets of the number components
     enum : size_t {
         COUNTRY_CODE_OFFSET = 0,
         LEADING_ZEROS_OFFSET = COUNTRY_CODE_OFFSET + COUNTRY_CODE_BITS,
@@ -55,10 +67,11 @@ class ShortPhoneNumber {
         return !(*this == other);
     }
 
+    /// Casts this object to a libphonenumber PhoneNumber object
     operator i18n::phonenumbers::PhoneNumber() const;
 
     /*
-     * Compares to another PhoneNumber using a fast collation heuristic
+     * Compares to another ShortPhoneNumber using a fast collation heuristic
      *
      * May not produce intuitive results for numbers with the same
      * country code but different lengths
@@ -72,26 +85,32 @@ class ShortPhoneNumber {
         return other._data - this->_data;
     }
 
+    /// Returns the number's country code
     google::protobuf::uint32 country_code() const {
         return get_masked(_data, COUNTRY_CODE_BITS, COUNTRY_CODE_OFFSET);
     }
 
+    /// Sets the number's country code
     void country_code(google::protobuf::uint32 value) {
         _data = set_masked(_data, (google::protobuf::uint64)value, COUNTRY_CODE_BITS, COUNTRY_CODE_OFFSET);
     }
 
+    /// Returns the national number
     google::protobuf::uint64 national_number() const {
         return get_masked(_data, NATIONAL_NUMBER_BITS, NATIONAL_NUMBER_OFFSET);
     }
 
+    /// Sets the national number
     void national_number(google::protobuf::uint64 value) {
         _data = set_masked(_data, value, NATIONAL_NUMBER_BITS, NATIONAL_NUMBER_OFFSET);
     }
 
+    /// Returns the number of leading zeros
     google::protobuf::uint64 leading_zeros() const {
         return get_masked(_data, LEADING_ZEROS_BITS, LEADING_ZEROS_OFFSET);
     }
 
+    /// Sets the number of leading zeros
     void leading_zeros(google::protobuf::uint64 value) {
         _data = set_masked(_data, value, LEADING_ZEROS_BITS, LEADING_ZEROS_OFFSET);
     }
@@ -100,5 +119,8 @@ class ShortPhoneNumber {
     google::protobuf::uint64 _data;
 };
 
-// If the size changes, we'll need to update the extension script too.
+/*
+ * If the size of the ShortPhoneNumber class changes for any reason, it will trip this assertion and remind us to
+ * update the SQL definition of the short_phone_number type.
+ */
 static_assert(sizeof(ShortPhoneNumber) == 8);