Fix further int-size ambiguities

src/stan/callbacks/json_writer.hpp

@@ -296,12 +296,15 @@ class json_writer final : public structured_writer {
    */
   void write(const std::string& key, int value) { write_int_like(key, value); }
 
-  /**
-   * Write a key-value pair where the value is an `std::size_t`.
-   * @param key Name of the value pair
-   * @param value `std::size_t` to write.
-   */
-  void write(const std::string& key, std::size_t value) {
+  /// Write a key-value pair with an unsigned long value.
+  void write(const std::string& key,
+             unsigned long value) override {  // NOLINT(runtime/int)
+    write_int_like(key, value);
+  }
+
+  /// Write a key-value pair with an unsigned long long value.
+  void write(const std::string& key,
+             unsigned long long value) override {  // NOLINT(runtime/int)
     write_int_like(key, value);
   }
 
@@ -321,7 +324,7 @@ class json_writer final : public structured_writer {
    * @param key Name of the value pair
    * @param value `unsigned int` to write.
    */
-  void write(const std::string& key, unsigned int value) {
+  void write(const std::string& key, unsigned int value) override {
     write_int_like(key, value);
   }
 

src/stan/callbacks/structured_writer.hpp

@@ -1,7 +1,6 @@
 #ifndef STAN_CALLBACKS_STRUCTURED_WRITER_HPP
 #define STAN_CALLBACKS_STRUCTURED_WRITER_HPP
 
-#include <cstdint>
 #include <stan/math/prim/fun/Eigen.hpp>
 #include <vector>
 #include <string>
@@ -65,12 +64,15 @@ class structured_writer {
    */
   virtual void write(const std::string& key, int value) {}
 
-  /**
-   * Write a key-value pair where the value is an `uint64_t`.
-   * @param key Name of the value pair
-   * @param value `uint64_t` to write.
-   */
-  virtual void write(const std::string& key, uint64_t value) {}
+  /// Write a key-value pair with an unsigned long value.
+  virtual void write(const std::string& key,
+                     unsigned long value  // NOLINT(runtime/int)
+  ) {}
+
+  /// Write a key-value pair with an unsigned long long value.
+  virtual void write(const std::string& key,
+                     unsigned long long value  // NOLINT(runtime/int)
+  ) {}
 
   /**
    * Write a key-value pair where the value is an `long long int`.
@@ -86,7 +88,7 @@ class structured_writer {
    * @param key Name of the value pair
    * @param value `unsigned int` to write.
    */
-  virtual void write(const std::string& key, uint32_t value) {}
+  virtual void write(const std::string& key, unsigned int value) {}
 
   /**
    * Write a key-value pair where the value is a double.

src/test/unit/callbacks/json_writer_test.cpp

@@ -1,6 +1,8 @@
 #include <stan/callbacks/json_writer.hpp>
 #include <test/unit/util.hpp>
 #include <gtest/gtest.h>
+#include <cstdint>
+#include <limits>
 #include <string>
 
 struct deleter_noop {
@@ -38,6 +40,22 @@ TEST_F(StanInterfaceCallbacksJsonWriter, begin_end_record) {
   EXPECT_EQ("{}", out);
 }
 
+TEST_F(StanInterfaceCallbacksJsonWriter, write_unsigned_through_base) {
+  stan::callbacks::structured_writer& base = writer;
+  base.begin_record();
+  base.write("uint", 42U);
+  base.write("ulong", 4294967295UL);
+  base.write("ullong", 18446744073709551615ULL);
+  base.write("size", std::size_t{5});
+  base.write("uint64", std::numeric_limits<std::uint64_t>::max());
+  base.end_record();
+  EXPECT_EQ(
+      "{\"uint\":42,\"ulong\":4294967295,"
+      "\"ullong\":18446744073709551615,\"size\":5,"
+      "\"uint64\":18446744073709551615}",
+      output_sans_whitespace(ss));
+}
+
 TEST_F(StanInterfaceCallbacksJsonWriter, begin_end_named_record) {
   writer.begin_record();
   writer.begin_record("name");