diff --git a/cmake/json_summary.cmake b/cmake/json_summary.cmake
index 31cc85c97..c48bbba78 100644
--- a/cmake/json_summary.cmake
+++ b/cmake/json_summary.cmake
@@ -1,40 +1,54 @@
-#############################################################################
-# json_feature_summary_begin()
-#
-# Initialize the feature summary buffer.
-#############################################################################
+# internal function used to implement json_feature(KEY_VALUE)
+function(_json_feature_key_value key value_var)
+    cmake_parse_arguments(args "NEGATE;RAW" "" "SWITCH;VALUES" ${ARGN})
 
-function(json_feature_summary_begin)
-    set(_JSON_FEATURE_SUMMARY_TEXT "" PARENT_SCOPE)
-endfunction()
-
-#############################################################################
-# json_feature_summary_end()
-#
-# Print the feature summary buffer.
-#############################################################################
-
-function(json_feature_summary_end)
-    if(NOT "${_JSON_FEATURE_SUMMARY_TEXT}" STREQUAL "")
-        message(STATUS "${_JSON_FEATURE_SUMMARY_TEXT}")
+    if(NOT "${args_SWITCH}" STREQUAL "")
+        if(${args_SWITCH})
+            # noop
+        else()
+            return()
+        endif()
     endif()
 
-    unset(_JSON_FEATURE_SUMMARY_TEXT PARENT_SCOPE)
+    if(${args_RAW})
+        set(value "${value_var}")
+    else()
+        set(value NO)
+        if(args_VALUES)
+            foreach(val ${args_VALUES})
+                if(${value_var} STREQUAL val)
+                    set(value ${val})
+                    break()
+                endif()
+            endforeach()
+        elseif(${args_NEGATE} AND NOT ${value_var} OR ${value_var})
+            set(value YES)
+        endif()
+    endif()
+    list(APPEND _JSON_FEATURE_SUMMARY KV "${key}" "${value}")
+    set(_JSON_FEATURE_SUMMARY "${_JSON_FEATURE_SUMMARY}" PARENT_SCOPE)
 endfunction()
 
 #############################################################################
 # json_feature(
-#     <var> <text>
+#     KEY_VALUE <key> <value_var>
 #     [VALUES <value>...]
-#     [NEGATE])
+#     [RAW] [NEGATE]
+#     [SWITCH <conditional_args>...])
 #
-# Append feature info using <text> and the boolean value of <var> converted
-# to YES/NO.
+# Append feature info using <key> as description text and the boolean value
+# of <value_var> converted to YES/NO.
 #
-# If additional values are given and <var> matches any of them, <var> is not
-# converted to YES/NO.
+# If RAW is specified, <value_var> is appended as is.
 #
-# If NEGATE is specified, the boolean value of <var> is negated.
+# If additional values are given and <value_var> matches any of them,
+# <value_var> is not converted to YES/NO.
+#
+# If NEGATE is specified, the boolean value of <value_var> is negated.
+#
+# If a conditional expression consisting of <conditional_args> is listed
+# following SWITCH, the feature is only added if the expression evaluates to
+# TRUE.
 #
 # ---
 #
@@ -49,99 +63,132 @@ endfunction()
 # Append raw text <text> to feature summary.
 #############################################################################
 
-function(json_feature)
-    if(NOT DEFINED _JSON_FEATURE_SUMMARY_TEXT)
-        message(FATAL_ERROR "json_feature() called before json_feature_summary_begin()")
-    endif()
-
-    set(var "")
-    set(text "")
-    if(${ARGC} EQUAL 1 OR ${ARGC} GREATER 1)
-        list(GET ARGN 0 var)
-    endif()
-    if(${ARGC} EQUAL 2 OR ${ARGC} GREATER 2)
-        list(GET ARGN 1 text)
-    endif()
-
-    # json_feature(RAW <text>)
-    if("${var}" STREQUAL RAW AND NOT "${text}" STREQUAL "")
-        set(text "   ${text}")
-    # json_feature(NEWLINE)
-    elseif("${var}" STREQUAL NEWLINE AND "${text}" STREQUAL "")
-        # noop
-    # json_feature(<var> <text> ...)
-    elseif(NOT "${var}" STREQUAL "" AND NOT "${text}" STREQUAL "")
-        cmake_parse_arguments(args "NEGATE" "" "VALUES" ${ARGN})
-
-        set(state NO)
-        if(args_VALUES)
-            foreach(value ${args_VALUES})
-                if(${var} STREQUAL value)
-                    set(state ${value})
-                    break()
-                endif()
-            endforeach()
-        elseif(${args_NEGATE} AND NOT ${var} OR ${var})
-            set(state YES)
+macro(json_feature mode)
+    if("${mode}" STREQUAL KEY_VALUE)
+        _json_feature_key_value(${ARGN})
+    elseif("${mode}" STREQUAL RAW)
+        list(LENGTH ARGN len)
+        if(${len} EQUAL 1)
+            list(APPEND _JSON_FEATURE_SUMMARY R ${ARGN} _)
+        else()
+            message(FATAL_ERROR "json_feature(RAW) called with incorrect arguments")
         endif()
-        set(text "   ${text} ${state}")
+    elseif("${mode}" STREQUAL NEWLINE)
+        list(APPEND _JSON_FEATURE_SUMMARY N _ _)
     else()
         message(FATAL_ERROR "json_feature() called with incorrect arguments")
     endif()
+endmacro()
 
-    # add preamble if buffer is empty
-    if("${_JSON_FEATURE_SUMMARY_TEXT}" STREQUAL "")
-        set(_JSON_FEATURE_SUMMARY_TEXT "[nohmann_json]: Feature summary:\n")
-    else()
-        set(_JSON_FEATURE_SUMMARY_TEXT "${_JSON_FEATURE_SUMMARY_TEXT}\n")
+#############################################################################
+# json_print_feature_summary()
+#
+# Build and print the feature summary.
+#############################################################################
+
+function(json_print_feature_summary)
+    if(NOT DEFINED _JSON_FEATURE_SUMMARY)
+        return()
+    endif()
+    if("${_JSON_FEATURE_SUMMARY}" STREQUAL "")
+        return()
     endif()
 
-    # append to buffer
-    set(_JSON_FEATURE_SUMMARY_TEXT "${_JSON_FEATURE_SUMMARY_TEXT}${text}" PARENT_SCOPE)
+    # calculate maximum key length
+    set(max_key_len 0)
+    set(feature_summary "${_JSON_FEATURE_SUMMARY}")
+    while(NOT "${feature_summary}" STREQUAL "")
+        list(GET feature_summary 0 mode)
+        list(GET feature_summary 1 key)
+        list(REMOVE_AT feature_summary 0 1 2)
+
+        if("${mode}" STREQUAL KV)
+            string(LENGTH "${key}" len)
+            if(${len} GREATER ${max_key_len})
+                set(max_key_len ${len})
+            endif()
+        endif()
+    endwhile()
+
+    # build feature summary string
+    set(last_newline FALSE)
+    set(text "[nohmann_json]: Feature summary:")
+    while(NOT "${_JSON_FEATURE_SUMMARY}" STREQUAL "")
+        list(GET _JSON_FEATURE_SUMMARY 0 mode)
+        list(GET _JSON_FEATURE_SUMMARY 1 key)
+        list(GET _JSON_FEATURE_SUMMARY 2 value)
+        list(REMOVE_AT _JSON_FEATURE_SUMMARY 0 1 2)
+
+        if("${mode}" STREQUAL KV)
+            # pad key to max_key_len with spaces
+            string(LENGTH "${key}" len)
+            math(EXPR pad_len "${max_key_len} - ${len}")
+            set(pad "")
+            if(${pad_len} GREATER 1)
+                foreach(i RANGE 1 ${pad_len})
+                    set(pad "${pad} ")
+                endforeach()
+            endif()
+
+            set(text "${text}\n   ${key}${pad} ${value}")
+            set(last_newline FALSE)
+        elseif("${mode}" STREQUAL R)
+            set(text "${text}\n   ${key}")
+            set(last_newline FALSE)
+        elseif("${mode}" STREQUAL N AND NOT ${last_newline})
+            if("${_JSON_FEATURE_SUMMARY}" STREQUAL "")
+                # skip trailing newline
+                break()
+            endif()
+            set(text "${text}\n")
+            set(last_newline TRUE)
+        endif()
+    endwhile()
+
+    message(STATUS "${text}")
 endfunction()
 
 #############################################################################
 # print feature summary
 #############################################################################
 
-json_feature_summary_begin()
+json_feature(KEY_VALUE "Build tests?" JSON_BuildTests)
 
-json_feature(JSON_BuildTests "Build tests?")
 if(JSON_BuildTests)
-    json_feature(JSON_32bitTest "Build the 32bit unit test?" VALUES AUTO ONLY)
-    json_feature(JSON_FastTests "Skip expensive/slow tests?")
+    json_feature(KEY_VALUE "Build the 32bit unit test?" JSON_32bitTest VALUES AUTO ONLY)
+    json_feature(KEY_VALUE "Skip expensive/slow tests?" JSON_FastTests)
 
     if(JSON_TestDataDirectory)
-        json_feature(RAW "Test data directory: ${JSON_TestDataDirectory}")
+        json_feature(KEY_VALUE "Test data directory:" "${JSON_TestDataDirectory}" RAW)
     else()
-        json_feature(RAW "Test data source: ${JSON_TEST_DATA_URL} (v${JSON_TEST_DATA_VERSION})")
+        json_feature(KEY_VALUE "Test data source:" "${JSON_TEST_DATA_URL} (v${JSON_TEST_DATA_VERSION})" RAW)
     endif()
 
-    json_feature(JSON_Valgrind "Execute test suite with Valgrind?")
+    json_feature(KEY_VALUE "Execute test suite with Valgrind?" JSON_Valgrind)
     if(JSON_Valgrind)
         string (REPLACE ";" " " memcheck_command "${CMAKE_MEMORYCHECK_COMMAND};${CMAKE_MEMORYCHECK_COMMAND_OPTIONS}")
-        json_feature(RAW "Valgrind command: ${memcheck_command}")
+        json_feature(KEY_VALUE "Valgrind command:" "${memcheck_command}" RAW)
     endif()
 
     list(JOIN JSON_TEST_CXX_STANDARDS_FEATURE_INFO " " test_cxx_standards)
     if(JSON_TEST_CXX_STANDARDS_FORCED)
         set(test_cxx_standards "${test_cxx_standards} (forced)")
     endif()
-    json_feature(RAW "Test C++ standards: ${test_cxx_standards}")
+    json_feature(KEY_VALUE "Test C++ standards:" "${test_cxx_standards}" RAW)
 endif()
 
 json_feature(NEWLINE)
 
-json_feature(JSON_Diagnostics "Diagnostics enabled?")
-json_feature(JSON_DisableEnumSerialization "Default integer enum serialization enabled?" NEGATE)
-json_feature(JSON_GlobalUDLs "Define user-defined string literals globally?")
-json_feature(JSON_ImplicitConversions "Implicit conversions enabled?")
-json_feature(JSON_LegacyDiscardedValueComparison "Legacy discarded value comparison enabled?")
+json_feature(KEY_VALUE "Diagnostics enabled?" JSON_Diagnostics SWITCH JSON_Diagnostics)
+json_feature(KEY_VALUE "Default integer enum serialization enabled?" JSON_DisableEnumSerialization NEGATE)
+json_feature(KEY_VALUE "Define user-defined string literals globally?" JSON_GlobalUDLs)
+json_feature(KEY_VALUE "Implicit conversions enabled?" JSON_ImplicitConversions)
+json_feature(KEY_VALUE "Legacy discarded value comparison enabled?" JSON_LegacyDiscardedValueComparison)
 
 json_feature(NEWLINE)
 
-json_feature(JSON_MultipleHeaders "Use the multi-header code?")
-json_feature(RAW "Include directory: ${NLOHMANN_JSON_INCLUDE_BUILD_DIR}")
-json_feature(JSON_SystemInclude "Include as system headers?")
+json_feature(KEY_VALUE "Use the multi-header code?" JSON_MultipleHeaders)
+json_feature(KEY_VALUE "Include directory:" "${NLOHMANN_JSON_INCLUDE_BUILD_DIR}" RAW)
+json_feature(KEY_VALUE "Include as system headers?" JSON_SystemInclude)
 
-json_feature_summary_end()
+json_print_feature_summary()